# @ohos.data.relationalStore (RDB Store)
The relational database (RDB) store manages data based on relational models. With the underlying SQLite database, the RDB store provides a complete mechanism for managing local databases. To satisfy different needs in complicated scenarios, the RDB store offers a series of APIs for performing operations such as adding, deleting, modifying, and querying data, and supports direct execution of SQL statements.
The **relationalStore** module provides the following functions:
- [RdbPredicates](#rdbpredicates): provides predicates indicating the nature, feature, or relationship of a data entity in an RDB store. It is used to define the operation conditions for an RDB store.
- [RdbStore](#rdbstore): provides APIs for managing data in an RDB store.
- [Resultset](#resultset): provides APIs for accessing the result set obtained from the RDB store.
> **NOTE**
>
> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Modules to Import
```js
import data_rdb from '@ohos.data.relationalStore';
```
## data_rdb.getRdbStore
getRdbStore(context: Context, config: StoreConfig, callback: AsyncCallback<RdbStore>): void
Obtains an RDB store. This API uses an asynchronous callback to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------------------------------- | ---- | ------------------------------------------------------------ |
| context | Context | Yes | Application context.
For details about the application context of the FA model, see [Context](js-apis-inner-app-context.md).
For details about the application context of the stage model, see [Context](js-apis-ability-context.md).|
| config | [StoreConfig](#storeconfig) | Yes | Configuration of the RDB store. |
| callback | AsyncCallback<[RdbStore](#rdbstore)> | Yes | Callback invoked to return the RDB store obtained. |
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ----------------------- |
| 14800010 | If failed delete database by invalid database name. |
| 14800011 | If failed open database by database corrupted. |
**Example**
FA model:
```js
// Obtain the context.
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
// Call getRdbStore.
const STORE_CONFIG = {
name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1
}
data_rdb.getRdbStore(context, STORE_CONFIG, function (err, rdbStore) {
if (err) {
console.info("Failed to get RdbStore, err: " + err)
return
}
if (rdbStore.openStatus == data_rdb.OpenStatus.ON_CREATE) {
console.log("RdbStore status is ON_CREATE")
} else if (rdbStore.openStatus == data_rdb.OpenStatus.ON_OPEN) {
console.log("RdbStore status is ON_OPEN")
} else {
return
}
console.log("Got RdbStore successfully.")
})
```
Stage model:
```ts
// Obtain the context.
import UIAbility from '@ohos.app.ability.UIAbility';
let context;
class EntryAbility extends UIAbility {
onWindowStageCreate(windowStage){
context = this.context
}
}
// Call getRdbStore.
const STORE_CONFIG = {
name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1
}
data_rdb.getRdbStore(context, STORE_CONFIG, function (err, rdbStore) {
if (err) {
console.info("Failed to get RdbStore, err: " + err)
return
}
if (rdbStore.openStatus == data_rdb.OpenStatus.ON_CREATE) {
console.log("RdbStore status is ON_CREATE")
} else if (rdbStore.openStatus == data_rdb.OpenStatus.ON_OPEN) {
console.log("RdbStore status is ON_OPEN")
} else {
return
}
console.log("Got RdbStore successfully.")
})
```
## data_rdb.getRdbStore
getRdbStore(context: Context, config: StoreConfig): Promise<RdbStore>
Obtains an RDB store. This API uses a promise to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | -------------------------------- | ---- | ------------------------------------------------------------ |
| context | Context | Yes | Application context.
For details about the application context of the FA model, see [Context](js-apis-inner-app-context.md).
For details about the application context of the stage model, see [Context](js-apis-ability-context.md).|
| config | [StoreConfig](#storeconfig) | Yes | Configuration of the RDB store. |
**Return value**
| Type | Description |
| ----------------------------------------- | --------------------------------- |
| Promise<[RdbStore](#rdbstore)> | Promise used to return the RDB store obtained.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ----------------------- |
| 14800010 | If failed delete database by invalid database name. |
| 14800011 | If failed open database by database corrupted. |
**Example**
FA model:
```js
// Obtain the context.
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
// Call getRdbStore.
const STORE_CONFIG = {
name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1
}
let promise = data_rdb.getRdbStore(context, STORE_CONFIG);
promise.then(async (rdbStore) => {
if (rdbStore.openStatus == data_rdb.OpenStatus.ON_CREATE) {
console.log("RdbStore status is ON_CREATE")
} else if (rdbStore.openStatus == data_rdb.OpenStatus.ON_OPEN) {
console.log("RdbStore status is ON_OPEN")
} else {
return
}
console.log("Got RdbStore successfully.")
}).catch((err) => {
console.log("Failed to get RdbStore, err: " + err)
})
```
Stage model:
```ts
// Obtain the context.
import UIAbility from '@ohos.app.ability.UIAbility';
let context;
class EntryAbility extends UIAbility {
onWindowStageCreate(windowStage){
context = this.context
}
}
// Call getRdbStore.
const STORE_CONFIG = {
name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1
}
let promise = data_rdb.getRdbStore(context, STORE_CONFIG);
promise.then(async (rdbStore) => {
if (rdbStore.openStatus == data_rdb.OpenStatus.ON_CREATE) {
console.log("RdbStore status is ON_CREATE")
} else if (rdbStore.openStatus == data_rdb.OpenStatus.ON_OPEN) {
console.log("RdbStore status is ON_OPEN")
} else {
return
}
console.log("Got RdbStore successfully.")
}).catch((err) => {
console.log("Failed to get RdbStore, err: " + err)
})
```
## data_rdb.deleteRdbStore
deleteRdbStore(context: Context, name: string, callback: AsyncCallback<void>): void
Deletes an RDB store. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------------------------------------ |
| context | Context | Yes | Application context.
For details about the application context of the FA model, see [Context](js-apis-inner-app-context.md).
For details about the application context of the stage model, see [Context](js-apis-ability-context.md).|
| name | string | Yes | Name of the RDB store to delete. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ----------------------- |
| 14800010 | If failed delete database by invalid database name. |
**Example**
FA model:
```js
// Obtain the context.
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
// Call deleteRdbStore.
data_rdb.deleteRdbStore(context, "RdbTest.db", function (err) {
if (err) {
console.info("Failed to delete RdbStore, err: " + err)
return
}
console.log("Deleted RdbStore successfully.")
})
```
Stage model:
```ts
// Obtain the context.
import UIAbility from '@ohos.app.ability.UIAbility';
let context;
class EntryAbility extends UIAbility {
onWindowStageCreate(windowStage){
context = this.context
}
}
// Call deleteRdbStore.
data_rdb.deleteRdbStore(context, "RdbTest.db", function (err) {
if (err) {
console.info("Failed to delete RdbStore, err: " + err)
return
}
console.log("Deleted RdbStore successfully.")
})
```
## data_rdb.deleteRdbStore
deleteRdbStore(context: Context, name: string): Promise<void>
Deletes an RDB store. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------- | ---- | ------------------------------------------------------------ |
| context | Context | Yes | Application context.
For details about the application context of the FA model, see [Context](js-apis-inner-app-context.md).
For details about the application context of the stage model, see [Context](js-apis-ability-context.md).|
| name | string | Yes | Name of the RDB store to delete. |
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ----------------------- |
| 14800010 | If failed delete database by invalid database name. |
**Example**
FA model:
```js
// Obtain the context.
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
// Call deleteRdbStore.
let promise = data_rdb.deleteRdbStore(context, "RdbTest.db")
promise.then(()=>{
console.log("Deleted RdbStore successfully.")
}).catch((err) => {
console.info("Failed to delete RdbStore, err: " + err)
})
```
Stage model:
```ts
// Obtain the context.
import UIAbility from '@ohos.app.ability.UIAbility';
let context;
class EntryAbility extends UIAbility {
onWindowStageCreate(windowStage){
context = this.context
}
}
// Call deleteRdbStore.
let promise = data_rdb.deleteRdbStore(context, "RdbTest.db")
promise.then(()=>{
console.log("Deleted RdbStore successfully.")
}).catch((err) => {
console.info("Failed to delete RdbStore, err: " + err)
})
```
## StoreConfig
Defines the RDB store configuration.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Type | Mandatory| Description |
| ------------- | ------------- | ---- | --------------------------------------------------------- |
| name | string | Yes | Database file name. |
| securityLevel | [SecurityLevel](#securitylevel) | Yes | Security level of the RDB store. |
| encrypt | boolean | No | Whether to encrypt the RDB store.
The value **true** means to encrypt the RDB store;
the value **false** means the opposite.|
## SecurityLevel
Enumerates the RDB store security levels.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name| Value | Description |
| ---- | ---- | ------------------------------------------------------------ |
| S1 | 1 | The RDB store security level is low. If data leakage occurs, minor impact will be caused on the database. For example, an RDB store that contains system data such as wallpapers.|
| S2 | 2 | The RDB store security level is medium. If data leakage occurs, moderate impact will be caused on the database. For example, an RDB store that contains information created by users or call records, such as audio or video clips.|
| S3 | 3 | The RDB store security level is high. If data leakage occurs, major impact will be caused on the database. For example, an RDB store that contains information such as user fitness, health, and location data.|
| S4 | 4 | The RDB store security level is critical. If data leakage occurs, severe impact will be caused on the database. For example, an RDB store that contains information such as authentication credentials and financial data.|
## ValueType
Defines the data types allowed.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Type | Description |
| ------- | -------------------- |
| number | Number. |
| string | String. |
| boolean | Boolean.|
## ValuesBucket
Defines the types of the key and value in a KV pair.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Key Type| Value Type |
| ------ | ----------------------------------------------------------- |
| string | [ValueType](#valuetype)\| Uint8Array \| null |
## SyncMode
Defines the database synchronization mode.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Value | Description |
| -------------- | ---- | ---------------------------------- |
| SYNC_MODE_PUSH | 0 | Data is pushed from a local device to a remote device.|
| SYNC_MODE_PULL | 1 | Data is pulled from a remote device to a local device. |
## SubscribeType
Defines the subscription type.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Value | Description |
| --------------------- | ---- | ------------------ |
| SUBSCRIBE_TYPE_REMOTE | 0 | Subscribe to remote data changes.|
## ConflictResolution10+
Defines the resolution to use when **insert()** and **update()** conflict.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Value | Description |
| -------------------- | ---- | ------------------------------------------------------------ |
| ON_CONFLICT_NONE | 0 | No operation is performed.|
| ON_CONFLICT_ROLLBACK | 1 | Abort the SQL statement and roll back the current transaction. |
| ON_CONFLICT_ABORT | 2 | Abort the current SQL statement and revert any changes made by the current SQL statement. However, the changes made by the previous SQL statement in the same transaction are retained and the transaction remains active.|
| ON_CONFLICT_FAIL | 3 | Abort the current SQL statement. The **FAIL** resolution does not revert previous changes made by the failed SQL statement or end the transaction.|
| ON_CONFLICT_IGNORE | 4 | Skip the rows that contain constraint violations and continue to process the subsequent rows of the SQL statement.|
| ON_CONFLICT_REPLACE | 5 | Delete pre-existing rows that cause the constraint violation before inserting or updating the current row, and continue to execute the command normally.|
## OpenStatus10+
Enumerates the RDB store status.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Value | Description |
| --------- | ---- | --------------------------------------------------- |
| ON_CREATE | 0 | The RDB store is created for the first time. |
| ON_OPEN | 1 | The RDB store is already created. |
## RdbPredicates
Defines the predicates for an RDB store. This class determines whether the conditional expression for the RDB store is true or false.
### constructor
constructor(name: string)
A constructor used to create an **RdbPredicates** object.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------ |
| name | string | Yes | Database table name.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
```
### inDevices
inDevices(devices: Array<string>): RdbPredicates
Sets an **RdbPredicates** to specify the remote devices to connect on the network during distributed database synchronization.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------------------- | ---- | -------------------------- |
| devices | Array<string> | Yes | IDs of the remote devices in the same network.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.inDevices(['12345678abcde'])
```
### inAllDevices
inAllDevices(): RdbPredicates
Sets an **RdbPredicates** to specify all remote devices on the network to connect during distributed database synchronization.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.inAllDevices()
```
### equalTo
equalTo(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")
```
### notEqualTo
notEqualTo(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value not equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notEqualTo("NAME", "lisi")
```
### beginWrap
beginWrap(): RdbPredicates
Adds a left parenthesis to the **RdbPredicates**.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** with a left parenthesis.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")
.beginWrap()
.equalTo("AGE", 18)
.or()
.equalTo("SALARY", 200.5)
.endWrap()
```
### endWrap
endWrap(): RdbPredicates
Adds a right parenthesis to the **RdbPredicates**.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** with a right parenthesis.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")
.beginWrap()
.equalTo("AGE", 18)
.or()
.equalTo("SALARY", 200.5)
.endWrap()
```
### or
or(): RdbPredicates
Adds the OR condition to the **RdbPredicates**.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** with the OR condition.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
.or()
.equalTo("NAME", "Rose")
```
### and
and(): RdbPredicates
Adds the AND condition to the **RdbPredicates**.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** with the AND condition.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
.and()
.equalTo("SALARY", 200.5)
```
### contains
contains(field: string, value: string): RdbPredicates
Sets an **RdbPredicates** to match a string containing the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | string | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.contains("NAME", "os")
```
### beginsWith
beginsWith(field: string, value: string): RdbPredicates
Sets an **RdbPredicates** to match a string that starts with the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | string | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.beginsWith("NAME", "os")
```
### endsWith
endsWith(field: string, value: string): RdbPredicates
Sets an **RdbPredicates** to match a string that ends with the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | string | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.endsWith("NAME", "se")
```
### isNull
isNull(field: string): RdbPredicates
Sets an **RdbPredicates** to match the field whose value is null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------ |
| field | string | Yes | Column name in the database table.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.isNull("NAME")
```
### isNotNull
isNotNull(field: string): RdbPredicates
Sets an **RdbPredicates** to match the field whose value is not null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------ |
| field | string | Yes | Column name in the database table.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.isNotNull("NAME")
```
### like
like(field: string, value: string): RdbPredicates
Sets an **RdbPredicates** to match a string that is similar to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | string | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.like("NAME", "%os%")
```
### glob
glob(field: string, value: string): RdbPredicates
Sets an **RdbPredicates** to match the specified string.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| field | string | Yes | Column name in the database table. |
| value | string | Yes | Value to match the **RdbPredicates**.
Wildcards are supported. * indicates zero, one, or multiple digits or characters. **?** indicates a single digit or character.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.glob("NAME", "?h*g")
```
### between
between(field: string, low: ValueType, high: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value within the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | -------------------------- |
| field | string | Yes | Column name in the database table. |
| low | [ValueType](#valuetype) | Yes | Minimum value to match the **RdbPredicates**. |
| high | [ValueType](#valuetype) | Yes | Maximum value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.between("AGE", 10, 50)
```
### notBetween
notBetween(field: string, low: ValueType, high: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value out of the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | -------------------------- |
| field | string | Yes | Column name in the database table. |
| low | [ValueType](#valuetype) | Yes | Minimum value to match the **RdbPredicates**. |
| high | [ValueType](#valuetype) | Yes | Maximum value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notBetween("AGE", 10, 50)
```
### greaterThan
greaterThan(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value greater than the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.greaterThan("AGE", 18)
```
### lessThan
lessThan(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value less than the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.lessThan("AGE", 20)
```
### greaterThanOrEqualTo
greaterThanOrEqualTo(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value greater than or equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.greaterThanOrEqualTo("AGE", 18)
```
### lessThanOrEqualTo
lessThanOrEqualTo(field: string, value: ValueType): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **ValueType** and value less than or equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ---------------------- |
| field | string | Yes | Column name in the database table. |
| value | [ValueType](#valuetype) | Yes | Value to match the **RdbPredicates**.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.lessThanOrEqualTo("AGE", 20)
```
### orderByAsc
orderByAsc(field: string): RdbPredicates
Sets an **RdbPredicates** to match the column with values sorted in ascending order.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------ |
| field | string | Yes | Column name in the database table.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.orderByAsc("NAME")
```
### orderByDesc
orderByDesc(field: string): RdbPredicates
Sets an **RdbPredicates** to match the column with values sorted in descending order.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------ |
| field | string | Yes | Column name in the database table.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.orderByDesc("AGE")
```
### distinct
distinct(): RdbPredicates
Sets an **RdbPredicates** to filter out duplicate records.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------------ |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object that can filter out duplicate records.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").distinct()
```
### limitAs
limitAs(value: number): RdbPredicates
Sets an **RdbPredicates** to specify the maximum number of records.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------- |
| value | number | Yes | Maximum number of records.|
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------------------ |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object that specifies the maximum number of records.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").limitAs(3)
```
### offsetAs
offsetAs(rowOffset: number): RdbPredicates
Sets an **RdbPredicates** to specify the start position of the returned result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| --------- | ------ | ---- | ---------------------------------- |
| rowOffset | number | Yes | Number of rows to offset from the beginning. The value is a positive integer.|
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------------------ |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object that specifies the start position of the returned result.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").offsetAs(3)
```
### groupBy
groupBy(fields: Array<string>): RdbPredicates
Sets an **RdbPredicates** to group rows that have the same value into summary rows.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------- | ---- | -------------------- |
| fields | Array<string> | Yes | Names of columns to group.|
**Return value**
| Type | Description |
| ------------------------------------ | ---------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object that groups rows with the same value.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.groupBy(["AGE", "NAME"])
```
### indexedBy
indexedBy(field: string): RdbPredicates
Sets an **RdbPredicates** object to specify the index column.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------- |
| field | string | Yes | Name of the index column.|
**Return value**
| Type | Description |
| ------------------------------------ | ------------------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object that specifies the index column.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.indexedBy("SALARY_INDEX")
```
### in
in(field: string, value: Array<ValueType>): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **Array<ValueType>** and value within the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------------------------ | ---- | --------------------------------------- |
| field | string | Yes | Column name in the database table. |
| value | Array<[ValueType](#valuetype)> | Yes | Array of **ValueType**s to match.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.in("AGE", [18, 20])
```
### notIn
notIn(field: string, value: Array<ValueType>): RdbPredicates
Sets an **RdbPredicates** to match the field with data type **Array<ValueType>** and value out of the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------------------------ | ---- | ------------------------------------- |
| field | string | Yes | Column name in the database table. |
| value | Array<[ValueType](#valuetype)> | Yes | Array of **ValueType**s to match.|
**Return value**
| Type | Description |
| ------------------------------------ | -------------------------- |
| [RdbPredicates](#rdbpredicates) | **RdbPredicates** object created.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notIn("NAME", ["Lisa", "Rose"])
```
## RdbStore
Provides methods to manage an RDB store.
Before using the following APIs, use [executeSql](#executesql) to initialize the database table structure and related data. For details, see [RDB Development](../../database/database-relational-guidelines.md).
### Attributes10+
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Type | Mandatory| Description |
| ------------ | ----------- | ---- | -------------------------------- |
| openStatus10+ | number | Yes | RDB store status. The value **0** indicates the **ON_CREATE** state, which means the RDB store is created for the first time. The value **1** indicates the **ON_OPEN** state, which means the RDB store is already created. |
### insert
insert(table: string, values: ValuesBucket, callback: AsyncCallback<number>):void
Inserts a row of data into a table. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ----------------------------- | ---- | ---------------------------------------------------------- |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Row of data to insert. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. If the operation is successful, the row ID will be returned. Otherwise, **-1** will be returned.|
**Example**
```js
const valueBucket = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
rdbStore.insert("EMPLOYEE", valueBucket, function (status, rowId) {
if (status) {
console.log("Failed to insert data");
return;
}
console.log("Inserted data successfully, rowId = " + rowId);
})
```
### insert10+
insert(table: string, values: ValuesBucket, conflict: ConflictResolution, callback: AsyncCallback<number>):void
Inserts a row of data into a table. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------- | ---- | ---------------------------------------------------------- |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Row of data to insert. |
| conflict | [ConflictResolution](#conflictresolution10) | Yes | Resolution used to resolve the conflict. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. If the operation is successful, the row ID will be returned. Otherwise, **-1** will be returned.|
**Example**
```js
const valueBucket = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
rdbStore.insert("EMPLOYEE", valueBucket, data_rdb.ConflictResolution.ON_CONFLICT_REPLACE, function (status, rowId) {
if (status) {
console.log("Failed to insert data");
return;
}
console.log("Inserted data successfully, rowId = " + rowId);
})
```
### insert
insert(table: string, values: ValuesBucket):Promise<number>
Inserts a row of data into a table. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------------- | ---- | -------------------------- |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Row of data to insert.|
**Return value**
| Type | Description |
| --------------------- | ------------------------------------------------- |
| Promise<number> | Promise used to return the result. If the operation is successful, the row ID will be returned. Otherwise, **-1** will be returned.|
**Example**
```js
const valueBucket = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let promise = rdbStore.insert("EMPLOYEE", valueBucket)
promise.then((rowId) => {
console.log("Inserted data successfully, rowId = " + rowId);
}).catch((status) => {
console.log("Failed to insert data");
})
```
### insert10+
insert(table: string, values: ValuesBucket, conflict: ConflictResolution):Promise<number>
Inserts a row of data into a table. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------- | ---- | -------------------------- |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Row of data to insert.|
| conflict | [ConflictResolution](#conflictresolution10) | Yes | Resolution used to resolve the conflict. |
**Return value**
| Type | Description |
| --------------------- | ------------------------------------------------- |
| Promise<number> | Promise used to return the result. If the operation is successful, the row ID will be returned. Otherwise, **-1** will be returned.|
**Example**
```js
const valueBucket = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let promise = rdbStore.insert("EMPLOYEE", valueBucket, data_rdb.ConflictResolution.ON_CONFLICT_REPLACE)
promise.then((rowId) => {
console.log("Inserted data successfully, rowId = " + rowId);
}).catch((status) => {
console.log("Failed to insert data");
})
```
### batchInsert
batchInsert(table: string, values: Array<ValuesBucket>, callback: AsyncCallback<number>):void
Batch inserts data into a table. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------ | ---- | ------------------------------------------------------------ |
| table | string | Yes | Name of the target table. |
| values | Array<[ValuesBucket](#valuesbucket)> | Yes | An array of data to insert. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, **-1** is returned.|
**Example**
```js
const valueBucket1 = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5])
}
const valueBucket2 = {
"NAME": "Jack",
"AGE": 19,
"SALARY": 101.5,
"CODES": new Uint8Array([6, 7, 8, 9, 10])
}
const valueBucket3 = {
"NAME": "Tom",
"AGE": 20,
"SALARY": 102.5,
"CODES": new Uint8Array([11, 12, 13, 14, 15])
}
let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
rdbStore.batchInsert("EMPLOYEE", valueBuckets, function(status, insertNum) {
if (status) {
console.log("batchInsert is failed, status = " + status);
return;
}
console.log("batchInsert is successful, the number of values that were inserted = " + insertNum);
})
```
### batchInsert
batchInsert(table: string, values: Array<ValuesBucket>):Promise<number>
Batch inserts data into a table. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------------------------------ | ---- | ---------------------------- |
| table | string | Yes | Name of the target table. |
| values | Array<[ValuesBucket](#valuesbucket)> | Yes | An array of data to insert.|
**Return value**
| Type | Description |
| --------------------- | ----------------------------------------------------------- |
| Promise<number> | Promise used to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, **-1** is returned.|
**Example**
```js
const valueBucket1 = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5])
}
const valueBucket2 = {
"NAME": "Jack",
"AGE": 19,
"SALARY": 101.5,
"CODES": new Uint8Array([6, 7, 8, 9, 10])
}
const valueBucket3 = {
"NAME": "Tom",
"AGE": 20,
"SALARY": 102.5,
"CODES": new Uint8Array([11, 12, 13, 14, 15])
}
let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
let promise = rdbStore.batchInsert("EMPLOYEE", valueBuckets);
promise.then((insertNum) => {
console.log("batchInsert is successful, the number of values that were inserted = " + insertNum);
}).catch((status) => {
console.log("batchInsert is failed, status = " + status);
})
```
### update
update(values: ValuesBucket, predicates: RdbPredicates, callback: AsyncCallback<number>):void
Updates data in the RDB store based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ------------------------------------------------------------ |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Update conditions specified by the **RdbPredicates** object. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the number of rows updated. |
**Example**
```js
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
rdbStore.update(valueBucket, predicates, function (err, rows) {
if (err) {
console.info("Failed to update data, err: " + err)
return
}
console.log("Updated row count: " + rows)
})
```
### update10+
update(values: ValuesBucket, predicates: RdbPredicates, conflict: ConflictResolution, callback: AsyncCallback<number>):void
Updates data in the RDB store based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------- | ---- | ------------------------------------------------------------ |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Update conditions specified by the **RdbPredicates** object. |
| conflict | [ConflictResolution](#conflictresolution10) | Yes | Resolution used to resolve the conflict. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the number of rows updated. |
**Example**
```js
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
rdbStore.update(valueBucket, predicates, data_rdb.ConflictResolution.ON_CONFLICT_REPLACE, function (err, rows) {
if (err) {
console.info("Failed to update data, err: " + err)
return
}
console.log("Updated row count: " + rows)
})
```
### update
update(values: ValuesBucket, predicates: RdbPredicates):Promise<number>
Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------------ | ------------------------------------ | ---- | ------------------------------------------------------------ |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Update conditions specified by the **RdbPredicates** object. |
**Return value**
| Type | Description |
| --------------------- | ----------------------------------------- |
| Promise<number> | Promise used to return the number of rows updated.|
**Example**
```js
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
let promise = rdbStore.update(valueBucket, predicates)
promise.then(async (rows) => {
console.log("Updated row count: " + rows)
}).catch((err) => {
console.info("Failed to update data, err: " + err)
})
```
### update10+
update(values: ValuesBucket, predicates: RdbPredicates, conflict: ConflictResolution):Promise<number>
Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------- | ---- | ------------------------------------------------------------ |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Update conditions specified by the **RdbPredicates** object. |
| conflict | [ConflictResolution](#conflictresolution10) | Yes | Resolution used to resolve the conflict. |
**Return value**
| Type | Description |
| --------------------- | ----------------------------------------- |
| Promise<number> | Promise used to return the number of rows updated.|
**Example**
```js
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
let promise = rdbStore.update(valueBucket, predicates, data_rdb.ConflictResolution.ON_CONFLICT_REPLACE)
promise.then(async (rows) => {
console.log("Updated row count: " + rows)
}).catch((err) => {
console.info("Failed to update data, err: " + err)
})
```
### update
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<number>):void
Updates data based on the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ------------------------------------------------------------ |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Update conditions specified by the **DataSharePredicates** object. |
| callback | AsyncCallback<number> | Yes | Callback invoked to return the number of rows updated. |
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Lisa")
rdbStore.update("EMPLOYEE", valueBucket, predicates, function (err, rows) {
if (err) {
console.info("Failed to update data, err: " + err)
return
}
console.log("Updated row count: " + rows)
})
```
### update
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates):Promise<number>
Updates data based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ------------------------------------------------------------ |
| table | string | Yes | Name of the target table. |
| values | [ValuesBucket](#valuesbucket) | Yes | Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.|
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Update conditions specified by the **DataSharePredicates** object. |
**Return value**
| Type | Description |
| --------------------- | ----------------------------------------- |
| Promise<number> | Promise used to return the number of rows updated.|
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
const valueBucket = {
"NAME": "Rose",
"AGE": 22,
"SALARY": 200.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Lisa")
let promise = rdbStore.update("EMPLOYEE", valueBucket, predicates)
promise.then(async (rows) => {
console.log("Updated row count: " + rows)
}).catch((err) => {
console.info("Failed to update data, err: " + err)
})
```
### delete
delete(predicates: RdbPredicates, callback: AsyncCallback<number>):void
Deletes data from the RDB store based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ----------------------------------------- |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Conditions specified by the **RdbPredicates** object for deleting data.|
| callback | AsyncCallback<number> | Yes | Callback invoked to return the number of rows deleted. |
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
rdbStore.delete(predicates, function (err, rows) {
if (err) {
console.info("Failed to delete data, err: " + err)
return
}
console.log("Deleted rows: " + rows)
})
```
### delete
delete(predicates: RdbPredicates):Promise<number>
Deletes data from the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ----------------------------------------- |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Conditions specified by the **RdbPredicates** object for deleting data.|
**Return value**
| Type | Description |
| --------------------- | ------------------------------- |
| Promise<number> | Promise used to return the number of rows deleted.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
let promise = rdbStore.delete(predicates)
promise.then((rows) => {
console.log("Deleted rows: " + rows)
}).catch((err) => {
console.info("Failed to delete data, err: " + err)
})
```
### delete
delete(table: string, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<number>):void
Deletes data from the RDB store based on the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | --------------------------------------------- |
| table | string | Yes | Name of the target table. |
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Conditions specified by the **DataSharePredicates** object for deleting data.|
| callback | AsyncCallback<number> | Yes | Callback invoked to return the number of rows deleted. |
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Lisa")
rdbStore.delete("EMPLOYEE", predicates, function (err, rows) {
if (err) {
console.info("Failed to delete data, err: " + err)
return
}
console.log("Deleted rows: " + rows)
})
```
### delete
delete(table: string, predicates: dataSharePredicates.DataSharePredicates):Promise<number>
Deletes data from the RDB store based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | --------------------------------------------- |
| table | string | Yes | Name of the target table. |
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Conditions specified by the **DataSharePredicates** object for deleting data.|
**Return value**
| Type | Description |
| --------------------- | ------------------------------- |
| Promise<number> | Promise used to return the number of rows deleted.|
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Lisa")
let promise = rdbStore.delete("EMPLOYEE", predicates)
promise.then((rows) => {
console.log("Deleted rows: " + rows)
}).catch((err) => {
console.info("Failed to delete data, err: " + err)
})
```
### query
query(predicates: RdbPredicates, columns: Array<string>, callback: AsyncCallback<ResultSet>):void
Queries data from the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ----------------------------------------------------------- |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Query conditions specified by the **RdbPredicates** object. |
| columns | Array<string> | Yes | Columns to query. If this parameter is not specified, the query applies to all columns. |
| callback | AsyncCallback<[ResultSet](#resultset)> | Yes | Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose")
rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], function (err, resultSet) {
if (err) {
console.info("Failed to query data, err: " + err)
return
}
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
})
```
### query
query(predicates: RdbPredicates, columns?: Array<string>):Promise<ResultSet>
Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ------------------------------------------------ |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Query conditions specified by the **RdbPredicates** object. |
| columns | Array<string> | No | Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
| Type | Description |
| ------------------------------------------------------- | -------------------------------------------------- |
| Promise<[ResultSet](#resultset)> | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose")
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"])
promise.then((resultSet) => {
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
}).catch((err) => {
console.info("Failed to query data, err: " + err)
})
```
### query
query(table: string, predicates: dataSharePredicates.DataSharePredicates, columns: Array<string>, callback: AsyncCallback<ResultSet>):void
Queries data from the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ----------------------------------------------------------- |
| table | string | Yes | Name of the target table. |
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Query conditions specified by the **DataSharePredicates** object. |
| columns | Array<string> | Yes | Columns to query. If this parameter is not specified, the query applies to all columns. |
| callback | AsyncCallback<[ResultSet](#resultset)> | Yes | Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Rose")
rdbStore.query("EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], function (err, resultSet) {
if (err) {
console.info("Failed to query data, err: " + err)
return
}
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
})
```
### query
query(table: string, predicates: dataSharePredicates.DataSharePredicates, columns?: Array<string>):Promise<ResultSet>
Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**System API**: This is a system API.
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ------------------------------------------------ |
| table | string | Yes | Name of the target table. |
| predicates | [dataSharePredicates.DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes | Query conditions specified by the **DataSharePredicates** object. |
| columns | Array<string> | No | Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
| Type | Description |
| ------------------------------------------------------- | -------------------------------------------------- |
| Promise<[ResultSet](#resultset)> | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Rose")
let promise = rdbStore.query("EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"])
promise.then((resultSet) => {
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
}).catch((err) => {
console.info("Failed to query data, err: " + err)
})
```
### remoteQuery
remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array<string> , callback: AsyncCallback<ResultSet>): void
Queries data from the RDB store of a remote device based on specified conditions. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------------------------------ | ---- | ----------------------------------------------------------- |
| device | string | Yes | Network ID of the remote device. |
| table | string | Yes | Name of the target table. |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Query conditions specified by the **RdbPredicates** object. |
| columns | Array<string> | Yes | Columns to query. If this parameter is not specified, the query applies to all columns. |
| callback | AsyncCallback<[ResultSet](#resultset)> | Yes | Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.greaterThan("id", 0)
rdbStore.remoteQuery("deviceId", "EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"],
function(err, resultSet){
if (err) {
console.info("Failed to remoteQuery, err: " + err)
return
}
console.info("ResultSet column names: " + resultSet.columnNames)
console.info("ResultSet column count: " + resultSet.columnCount)
})
```
### remoteQuery
remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array<string>): Promise<ResultSet>
Queries data from the RDB store of a remote device based on specified conditions. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ------------------------------------------------ |
| device | string | Yes | Network ID of the remote device. |
| table | string | Yes | Name of the target table. |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | Query conditions specified by the **RdbPredicates** object. |
| columns | Array<string> | Yes | Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
| Type | Description |
| ------------------------------------------------------------ | -------------------------------------------------- |
| Promise<[ResultSet](#resultset)> | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.greaterThan("id", 0)
let promise = rdbStore.remoteQuery("deviceId", "EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"])
promise.then((resultSet) => {
console.info("ResultSet column names: " + resultSet.columnNames)
console.info("ResultSet column count: " + resultSet.columnCount)
}).catch((err) => {
console.info("Failed to remoteQuery , err: " + err)
})
```
### querySql
querySql(sql: string, bindArgs: Array<ValueType>, callback: AsyncCallback<ResultSet>):void
Queries data using the specified SQL statement. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------------------------ | ---- | ----------------------------------------------------------- |
| sql | string | Yes | SQL statement to run. |
| bindArgs | Array<[ValueType](#valuetype)> | Yes | Arguments in the SQL statement. |
| callback | AsyncCallback<[ResultSet](#resultset)> | Yes | Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
rdbStore.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = ?", ['sanguo'], function (err, resultSet) {
if (err) {
console.info("Failed to query data, err: " + err)
return
}
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
})
```
### querySql
querySql(sql: string, bindArgs?: Array<ValueType>):Promise<ResultSet>
Queries data using the specified SQL statement. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------ | ---- | --------------------- |
| sql | string | Yes | SQL statement to run.|
| bindArgs | Array<[ValueType](#valuetype)> | No | Arguments in the SQL statement. |
**Return value**
| Type | Description |
| ------------------------------------------------------- | -------------------------------------------------- |
| Promise<[ResultSet](#resultset)> | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let promise = rdbStore.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = ?", ['sanguo'])
promise.then((resultSet) => {
console.log("ResultSet column names: " + resultSet.columnNames)
console.log("ResultSet column count: " + resultSet.columnCount)
}).catch((err) => {
console.info("Failed to query data, err: " + err)
})
```
### executeSql
executeSql(sql: string, bindArgs: Array<ValueType>, callback: AsyncCallback<void>):void
Executes an SQL statement that contains specified arguments but returns no value. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------ | ---- | ---------------------- |
| sql | string | Yes | SQL statement to run. |
| bindArgs | Array<[ValueType](#valuetype)> | Yes | Arguments in the SQL statement. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```js
const SQL_CREATE_TABLE = "CREATE TABLE IF NOT EXISTS EMPLOYEE (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INTEGER, SALARY REAL, CODES BLOB)"
rdbStore.executeSql(SQL_CREATE_TABLE, null, function(err) {
if (err) {
console.info("Failed to execute SQL, err: " + err)
return
}
console.info('Create table done.')
})
```
### executeSql
executeSql(sql: string, bindArgs?: Array<ValueType>):Promise<void>
Executes an SQL statement that contains specified arguments but returns no value. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------ | ---- | --------------------- |
| sql | string | Yes | SQL statement to run.|
| bindArgs | Array<[ValueType](#valuetype)> | No | Arguments in the SQL statement. |
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
const SQL_CREATE_TABLE = "CREATE TABLE IF NOT EXISTS EMPLOYEE (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INTEGER, SALARY REAL, CODES BLOB)"
let promise = rdbStore.executeSql(SQL_CREATE_TABLE)
promise.then(() => {
console.info('Create table done.')
}).catch((err) => {
console.info("Failed to execute SQL, err: " + err)
})
```
### beginTransaction
beginTransaction():void
Starts the transaction before executing an SQL statement.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Example**
```js
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
const STORE_CONFIG = { name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1}
data_rdb.getRdbStore(context, STORE_CONFIG, async function (err, rdbStore) {
rdbStore.beginTransaction()
const valueBucket = {
"name": "lisi",
"age": 18,
"salary": 100.5,
"blobType": new Uint8Array([1, 2, 3]),
}
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
})
```
### commit
commit():void
Commits the executed SQL statements.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Example**
```js
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
const STORE_CONFIG = { name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1}
data_rdb.getRdbStore(context, STORE_CONFIG, async function (err, rdbStore) {
rdbStore.beginTransaction()
const valueBucket = {
"name": "lisi",
"age": 18,
"salary": 100.5,
"blobType": new Uint8Array([1, 2, 3]),
}
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
})
```
### rollBack
rollBack():void
Rolls back the SQL statements that have been executed.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Example**
```js
import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext()
const STORE_CONFIG = { name: "RdbTest.db",
securityLevel: data_rdb.SecurityLevel.S1}
data_rdb.getRdbStore(context, STORE_CONFIG, async function (err, rdbStore) {
try {
rdbStore.beginTransaction()
const valueBucket = {
"id": 1,
"name": "lisi",
"age": 18,
"salary": 100.5,
"blobType": new Uint8Array([1, 2, 3]),
}
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
} catch (e) {
rdbStore.rollBack()
}
})
```
### backup
backup(destName:string, callback: AsyncCallback<void>):void
Backs up an RDB store. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------ |
| destName | string | Yes | Name of the RDB store backup file.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```js
rdbStore.backup("dbBackup.db", function(err) {
if (err) {
console.info('Backup failed, err: ' + err)
return
}
console.info('Backup success.')
})
```
### backup
backup(destName:string): Promise<void>
Backs up an RDB store. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------ | ---- | ------------------------ |
| destName | string | Yes | Name of the RDB store backup file.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
let promiseBackup = rdbStore.backup("dbBackup.db")
promiseBackup.then(()=>{
console.info('Backup success.')
}).catch((err)=>{
console.info('Backup failed, err: ' + err)
})
```
### restore
restore(srcName:string, callback: AsyncCallback<void>):void
Restores an RDB store from a backup file. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------ |
| srcName | string | Yes | Name of the RDB store backup file.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```js
rdbStore.restore("dbBackup.db", function(err) {
if (err) {
console.info('Restore failed, err: ' + err)
return
}
console.info('Restore success.')
})
```
### restore
restore(srcName:string): Promise<void>
Restores an RDB store from a backup file. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------ | ---- | ------------------------ |
| srcName | string | Yes | Name of the RDB store backup file.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
let promiseRestore = rdbStore.restore("dbBackup.db")
promiseRestore.then(()=>{
console.info('Restore success.')
}).catch((err)=>{
console.info('Restore failed, err: ' + err)
})
```
### setDistributedTables
setDistributedTables(tables: Array<string>, callback: AsyncCallback<void>): void
Sets distributed tables. This API uses an asynchronous callback to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ---------------------- |
| tables | Array<string> | Yes | Names of the distributed tables to set.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```js
rdbStore.setDistributedTables(["EMPLOYEE"], function (err) {
if (err) {
console.info('Failed to set distributed tables, err: ' + err)
return
}
console.info('Set distributed tables successfully.')
})
```
### setDistributedTables
setDistributedTables(tables: Array<string>): Promise<void>
Sets distributed tables. This API uses a promise to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------------------- | ---- | ------------------------ |
| tables | Array<string> | Yes | Names of the distributed tables to set.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
let promise = rdbStore.setDistributedTables(["EMPLOYEE"])
promise.then(() => {
console.info("Set distributed tables successfully.")
}).catch((err) => {
console.info("Failed to set distributed tables, err: " + err)
})
```
### obtainDistributedTableName
obtainDistributedTableName(device: string, table: string, callback: AsyncCallback<string>): void
Obtains the distributed table name for a remote device based on the local table name. This API uses an asynchronous callback to return the result. The distributed table name is required when the RDB store of a remote device is queried.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | --------------------------- | ---- | ------------------------------------------------------------ |
| device | string | Yes | Remote device. |
| table | string | Yes | Local table name. |
| callback | AsyncCallback<string> | Yes | Callback invoked to return the result. If the operation succeeds, the distributed table name of the remote device is returned.|
**Example**
```js
rdbStore.obtainDistributedTableName("12345678abcde", "EMPLOYEE", function (err, tableName) {
if (err) {
console.info('Failed to obtain DistributedTableName, err: ' + err)
return
}
console.info('Obtained distributed table name successfully, tableName=.' + tableName)
})
```
### obtainDistributedTableName
obtainDistributedTableName(device: string, table: string): Promise<string>
Obtains the distributed table name for a remote device based on the local table name. This API uses a promise to return the result. The distributed table name is required when the RDB store of a remote device is queried.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------- |
| device | string | Yes | Remote device.|
| table | string | Yes | Local table name.|
**Return value**
| Type | Description |
| --------------------- | ----------------------------------------------------- |
| Promise<string> | Promise used to return the result. If the operation succeeds, the distributed table name of the remote device is returned.|
**Example**
```js
let promise = rdbStore.obtainDistributedTableName("12345678abcde", "EMPLOYEE")
promise.then((tableName) => {
console.info('Obtained distributed table name successfully, tableName= ' + tableName)
}).catch((err) => {
console.info('Failed to obtain DistributedTableName, err: ' + err)
})
```
### sync
sync(mode: SyncMode, predicates: RdbPredicates, callback: AsyncCallback<Array<[string, number]>>): void
Synchronizes data between devices. This API uses an asynchronous callback to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | -------------------------------------------------- | ---- | ------------------------------------------------------------ |
| mode | [SyncMode](#syncmode) | Yes | Data synchronization mode. The value can be **push** or **pull**. |
| predicates | [RdbPredicates](#rdbpredicates) | Yes | **RdbPredicates** object that specifies the data and devices to synchronize. |
| callback | AsyncCallback<Array<[string, number]>> | Yes | Callback invoked to send the synchronization result to the caller.
**string** indicates the device ID.
**number** indicates the synchronization status of that device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
**Example**
```js
let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.inDevices(['12345678abcde'])
rdbStore.sync(data_rdb.SyncMode.SYNC_MODE_PUSH, predicates, function (err, result) {
if (err) {
console.log('Sync failed, err: ' + err)
return
}
console.log('Sync done.')
for (let i = 0; i < result.length; i++) {
console.log('device=' + result[i][0] + ' status=' + result[i][1])
}
})
```
### sync
sync(mode: SyncMode, predicates: RdbPredicates): Promise<Array<[string, number]>>
Synchronizes data between devices. This API uses a promise to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------------------------------------ | ---- | ------------------------------ |
| mode | [SyncMode](#syncmode) | Yes | Data synchronization mode. The value can be **push** or **pull**.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes | **RdbPredicates** object that specifies the data and devices to synchronize. |
**Return value**
| Type | Description |
| -------------------------------------------- | ------------------------------------------------------------ |
| Promise<Array<[string, number]>> | Promise used to send the synchronization result.
**string** indicates the device ID.
**number** indicates the synchronization status of that device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
**Example**
```js
let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.inDevices(['12345678abcde'])
let promise = rdbStore.sync(data_rdb.SyncMode.SYNC_MODE_PUSH, predicates)
promise.then((resultSet) =>{
console.log('Sync done.')
for (let i = 0; i < resultSet.length; i++) {
console.log('device=' + resultSet[i][0] + ' status=' + resultSet[i][1])
}
}).catch((err) => {
console.log('Sync failed')
})
```
### on('dataChange')
on(event: 'dataChange', type: SubscribeType, observer: Callback<Array<string>>): void
Registers an observer for this RDB store. When the data in the RDB store changes, a callback is invoked to return the data changes.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ----------------------------------- | ---- | ------------------------------------------- |
| event | string | Yes | The value is'dataChange', which indicates a data change event. |
| type | [SubscribeType](#subscribetype) | Yes | Subscription type to register.|
| observer | Callback<Array<string>> | Yes | Observer that listens for the data changes in the RDB store. |
**Example**
```js
function storeObserver(devices) {
for (let i = 0; i < devices.length; i++) {
console.log('device=' + devices[i] + ' data changed')
}
}
try {
rdbStore.on('dataChange', data_rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver)
} catch (err) {
console.log('Failed to register observer')
}
```
### off('dataChange')
off(event:'dataChange', type: SubscribeType, observer: Callback<Array<string>>): void
Unregisters the observer of the specified type from the RDB store. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------------------- | ---- | ------------------------------------------ |
| event | string | Yes | The value is'dataChange', which indicates a data change event. |
| type | [SubscribeType](#subscribetype) | Yes | Subscription type to register. |
| observer | Callback<Array<string>> | Yes | Data change observer registered. |
**Example**
```js
function storeObserver(devices) {
for (let i = 0; i < devices.length; i++) {
console.log('device=' + devices[i] + ' data changed')
}
}
try {
rdbStore.off('dataChange', data_rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver)
} catch (err) {
console.log('Failed to unregister observer')
}
```
## ResultSet
Provides APIs to access the result set obtained by querying the RDB store. A result set is a set of results returned after **query()** is called.
### Usage
Obtain the **resultSet** object by [RdbStore.query()](#query).
```js
import dataRdb from '@ohos.data.rdb';
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
predicates.equalTo("AGE", 18);
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
console.log(TAG + "resultSet columnNames:" + resultSet.columnNames);
console.log(TAG + "resultSet columnCount:" + resultSet.columnCount);
});
```
### Attributes
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
| Name | Type | Mandatory| Description |
| ------------ | ------------------- | ---- | -------------------------------- |
| columnNames | Array<string> | Yes | Names of all columns in the result set. |
| columnCount | number | Yes | Number of columns in the result set. |
| rowCount | number | Yes | Number of rows in the result set. |
| rowIndex | number | Yes | Index of the current row in the result set. |
| isAtFirstRow | boolean | Yes | Whether the cursor is in the first row of the result set. |
| isAtLastRow | boolean | Yes | Whether the cursor is in the last row of the result set. |
| isEnded | boolean | Yes | Whether the cursor is after the last row of the result set.|
| isStarted | boolean | Yes | Whether the cursor has been moved. |
| isClosed | boolean | Yes | Whether the result set is closed. |
### getColumnIndex
getColumnIndex(columnName: string): number
Obtains the column index based on the column name.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ---------- | ------ | ---- | -------------------------- |
| columnName | string | Yes | Column name.|
**Return value**
| Type | Description |
| ------ | ------------------ |
| number | Column index obtained.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800013 | The column value is null or the column type is incompatible. |
**Example**
```js
resultSet.goToFirstRow();
const id = resultSet.getLong(resultSet.getColumnIndex("ID"));
const name = resultSet.getString(resultSet.getColumnIndex("NAME"));
const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));
const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));
```
### getColumnName
getColumnName(columnIndex: number): string
Obtains the column name based on the specified column index.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | -------------------------- |
| columnIndex | number | Yes | Column index.|
**Return value**
| Type | Description |
| ------ | ------------------ |
| string | Column name obtained.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800013 | The column value is null or the column type is incompatible. |
**Example**
```js
const id = resultSet.getColumnName(0);
const name = resultSet.getColumnName(1);
const age = resultSet.getColumnName(2);
```
### goTo
goTo(offset:number): boolean
Moves the cursor to the row based on the specified offset.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ---------------------------- |
| offset | number | Yes | Offset relative to the current position.|
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise= rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goTo(1);
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### goToRow
goToRow(position: number): boolean
Moves to the specified row in the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------ | ---- | ------------------------ |
| position | number | Yes | Destination position to move to.|
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.(5);
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### goToFirstRow
goToFirstRow(): boolean
Moves to the first row of the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToFirstRow();
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### goToLastRow
goToLastRow(): boolean
Moves to the last row of the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToLastRow();
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### goToNextRow
goToNextRow(): boolean
Moves to the next row in the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToNextRow();
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### goToPreviousRow
goToPreviousRow(): boolean
Moves to the previous row in the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Return value**
| Type | Description |
| ------- | --------------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |
**Example**
```js
let predicates = new dataRdb.RdbPredicates("EMPLOYEE");
let promise = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToPreviousRow();
resultSet.close();
}).catch((err) => {
console.log('query failed');
});
```
### getBlob
getBlob(columnIndex: number): Uint8Array
Obtains the value in the form of a byte array based on the specified column and the current row.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | ----------------------- |
| columnIndex | number | Yes | Index of the target column, starting from 0.|
**Return value**
| Type | Description |
| ---------- | -------------------------------- |
| Uint8Array | Value obtained.|
**Example**
```js
const codes = resultSet.getBlob(resultSet.getColumnIndex("CODES"));
```
### getString
getString(columnIndex: number): string
Obtains the value in the form of a string based on the specified column and the current row.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | ----------------------- |
| columnIndex | number | Yes | Index of the target column, starting from 0.|
**Return value**
| Type | Description |
| ------ | ---------------------------- |
| string | String obtained.|
**Example**
```js
const name = resultSet.getString(resultSet.getColumnIndex("NAME"));
```
### getLong
getLong(columnIndex: number): number
Obtains the value of the Long type based on the specified column and the current row.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | ----------------------- |
| columnIndex | number | Yes | Index of the target column, starting from 0.|
**Return value**
| Type | Description |
| ------ | -------------------------- |
| number | Value obtained.|
**Example**
```js
const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));
```
### getDouble
getDouble(columnIndex: number): number
Obtains the value of the double type based on the specified column and the current row.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | ----------------------- |
| columnIndex | number | Yes | Index of the target column, starting from 0.|
**Return value**
| Type | Description |
| ------ | ---------------------------- |
| number | Value obtained.|
**Example**
```js
const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));
```
### isColumnNull
isColumnNull(columnIndex: number): boolean
Checks whether the value in the specified column is null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ----------- | ------ | ---- | ----------------------- |
| columnIndex | number | Yes | Index of the target column, starting from 0.|
**Return value**
| Type | Description |
| ------- | --------------------------------------------------------- |
| boolean | Returns **true** if the value is null; returns **false** otherwise.|
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800013 | The column value is null or the column type is incompatible. |
**Example**
```js
const isColumnNull = resultSet.isColumnNull(resultSet.getColumnIndex("CODES"));
```
### close
close(): void
Closes this result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Example**
```js
let predicatesClose = new dataRdb.RdbPredicates("EMPLOYEE");
let promiseClose = rdbStore.query(predicatesClose, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promiseClose.then((resultSet) => {
resultSet.close();
}).catch((err) => {
console.log('resultset close failed');
});
```
**Error codes**
For details about the error codes, see [RDB Error Codes](../errorcodes/errorcode-data-rdb.md).
| **ID**| **Error Message** |
| ------------ | ------------------------------------------------------------ |
| 14800012 | The result set is empty or the specified location is invalid. |