| createKVManager(config: KVManagerConfig, callback: AsyncCallback<KVManager>): void<br>createKVManager(config: KVManagerConfig): Promise<KVManager> | Creates a **KVManager** object for database management.|
| getKVStore<TextendsKVStore>(storeId: string, options: Options, callback: AsyncCallback<T>): void<br>getKVStore<TextendsKVStore>(storeId: string, options: Options): Promise<T> | Obtains a KV store with the specified **Options** and **storeId**.|
console.error(`An unexpected error occurred.code is ${e.code},message is ${e.message}`);
}
```
> **NOTE**<br>
>
> For data synchronization between networked devices, you are advised to open the distributed KV store during application startup to obtain the database handle. With this database handle (`kvStore` in this example), you can perform operations, such as inserting data into the KV store, without creating the KV store repeatedly during the lifecycle of the handle.
5. Subscribe to changes in the distributed data.
The following is the sample code for subscribing to the data changes of a single KV store:
@@ -13,7 +13,9 @@ This module provides the following functions:
>**NOTE**<br/>
>
>The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>- The APIs provided by this module are no longer maintained since API version 9. You are advised to use `@ohos.data.distributedKVStore`](js-apis-distributedKVStore.md).
>
>- The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Modules to Import
...
...
@@ -39,56 +41,28 @@ Creates a **KVManager** instance to manage KV stores. This API uses an asynchron
| callback | AsyncCallback<[KVManager](#kvmanager)> | Yes | Callback invoked to return the **KVManager** instance created.|
console.log("Failed to create KVManager: "+JSON.stringify(err));
});
```
## KVManagerConfig
...
...
@@ -168,7 +118,6 @@ Provides configuration of the **KVManager** object, including the bundle name an
| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| context<sup>9+<sup> | Context | Yes| Application context.<br>For the application context of the FA model, see [Context](js-apis-Context.md).<br>For the application context of the stage model, see [Context](js-apis-ability-context.md).|
| userInfo | [UserInfo](#userinfo) | Yes | User information.|
| createIfMissing | boolean | No| Whether to create a KV store if no database file exists. By default, a KV store is created.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.Core |
| encrypt | boolean | No|Whether to encrypt database files. By default, database files are not encrypted.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.Core |
| backup | boolean | No|Whether to back up database files. By default, database files are backed up. <br>**System capability**: SystemCapability.DistributedDataManager.KVStore.Core |
...
...
@@ -642,8 +591,8 @@ Enumerates the KV store types.
| SINGLE_VERSION | 1 | Single KV store.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.Core|
| DEVICE_COLLABORATION | 0 | Device KV store.<br> The device KV store manages data by device, which eliminates conflicts. Data can be queried by device.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore |
| SINGLE_VERSION | 1 | Single KV store.<br> The single KV store does not differentiate data by device. If the same key is modified by different devices, the data will be overwritten.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.Core|
| MULTI_VERSION | 2 | Multi-version KV store. This type is not supported currently.<br>**System capability**: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore|
...
...
@@ -682,12 +631,12 @@ Defines the schema of a KV store. You can create a **Schema** object and place i
| predicates | [DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes |Conditions for deleting data. If this parameter is **null**, define the processing logic.|
| callback | AsyncCallback<void> | Yes |Callback invoked to return the result. |
| predicates | [DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes |Conditions for deleting data. If this parameter is **null**, define the processing logic.|
**Return value**
| Type | Description |
| ------ | ------- |
| Promise<void> |Promise that returns no value.|
| file | string | Yes | Name of the RDB store. The value cannot be empty or exceed [MAX_KEY_LENGTH](#constants).|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is the error object.|
| file | string | Yes | Name of the database file. The value cannot be empty or exceed [MAX_KEY_LENGTH](#constants).|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error object.|
| files | Array<string> | Yes | Name of the backup file to delete. The value cannot be empty or exceed [MAX_KEY_LENGTH](#constants). |
| callback | AsyncCallback<Array<[string, number]>> | Yes | Callback invoked to return the name of the backup file deleted and the operation result. |
Obtains a **KvStoreResultSet** object that matches the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
| predicates | [DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes |**DataSharePredicates** object to match. If this parameter is **null**, define the processing logic. |
| callback |AsyncCallback<[KvStoreResultSet](#kvstoreresultset8)> | Yes |Callback invoked to return the **KvStoreResultSet** object obtained.|
| predicates |[DataSharePredicates](js-apis-data-dataSharePredicates.md#datasharepredicates) | Yes |**DataSharePredicates** object to match. If this parameter is **null**, define the processing logic. |
**Return value**
| Type | Description |
| ------ | ------- |
|Promise<[KvStoreResultSet](#kvstoreresultset8)> |Promise that returns no value.|
Synchronizes the KV store manually. For details about the synchronization modes of the distributed data service, see [Distributed Data Service Overview](../../database/database-mdds-overview.md).
Subscribes to synchronization complete events. This API returns the result synchronously.
Synchronizes the KV store manually. For details about the synchronization modes of the distributed data service, see [Distributed Data Service Overview](../../database/database-mdds-overview.md).
Synchronizes the KV store manually. This API returns the result synchronously. For details about the synchronization modes of the distributed data service, see [Distributed Data Service Overview](../../database/database-mdds-overview.md).
Synchronizes the KV store manually. This API returns the result synchronously. For details about the synchronization modes of the distributed data service, see [Distributed Data Service Overview](../../database/database-mdds-overview.md).
The number of subscriptions has reached the limit for **on('dataChange')**.
**Possible Causes**
The number of subscriptions has reached the limit for **on('dataChange')**.
**Solution**
Unregister unnecessary subscriptions and try again.
## 15100002 Parameter Configuration Changes
**Error Message**
Open existed database with changed options.
**Description**
The **options** configuration changes when **getKVStore()** is called to obtain a KV store.
**Possible Causes**
The possible causes are as follows:
1. An existing **storeId** is used to create a KV store.
2. You want to change the **options** parameter of a KV store.
**Solution**
1. When creating a KV store, do not use a duplicate **storeId**.
2. Currently, the **options** parameter of a KV store cannot be changed. To apply the change, delete the KV store and create a KV store with the required **options** settings.
## 15100003 KV Store Corrupted
**Error Message**
Database corrupted.
**Description**
The target KV store is corrupted.
**Possible Causes**
The target KV store is corrupted.
**Solution**
1. Restore the KV store from a backup file.
2. If no backup file is available, delete the corrupted KV store and create a new one.
## 15100004 Failed to Find Data
**Error Message**
Not found.
**Description**
Related data is found when **deleteKVStore()**, **delete()**, **deleteBatch()**, or **get()** is called.
**Possible Causes**
The possible causes are as follows:
1. The KV store to delete does not exist or has been deleted.
2. The data queried does not exist or has been deleted.
3. The data to delete does not exist or has been deleted.
**Solution**
1. Before deleting a KV store, check that the KV store exists.
2. When querying data in a KV store, check whether the query keywords are correct.
3. When deleting data from a KV store, check that the keyword for the deletion is correct and the data to delete exists.
## 15100005 KV Store or Result Set Closed
**Error Message**
Database or result set already closed.
**Description**
The KV store or result set to operate is already closed.
**Possible Causes**
The KV store or result set is closed manually before the operation.
