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提交 1dfda209 编写于 作者: A Annie_wang
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update docs 

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>
上级 9d66e5f2
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Showing with 95 addition and 74 deletion
en/application-dev/reference/apis/js-apis-data-resultset.md
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......@@ -6,26 +6,25 @@ A result set is a set of results returned after the relational database (RDB) qu
>
> 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.
## Usage
You need to use [RdbStore.query()](js-apis-data-rdb.md#query) to obtain a **resultSet** object.
```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"])
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);})
console.log(TAG + "resultSet columnCount:" + resultSet.columnCount);
});
```
## ResultSet
Provides methods to access the result set, which is obtained by querying the RDB store.
### Attributes
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -42,7 +41,6 @@ Provides methods to access the result set, which is obtained by querying the RDB
| isStarted | boolean | Yes| Whether the cursor has been moved.|
| isClosed | boolean | Yes| Whether the result set is closed.|
### getColumnIndex
getColumnIndex(columnName: string): number
......@@ -52,25 +50,27 @@ 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 specified.|
**Return value**
| Type| Description|
| -------- | -------- |
| number | Index of the column obtained.|
**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"))
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
......@@ -80,23 +80,25 @@ Obtains the column name based on the column index.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Column index specified.|
**Return value**
| Type| Description|
| -------- | -------- |
| string | Column name obtained.|
**Example**
```js
const id = resultSet.getColumnName(0)
const name = resultSet.getColumnName(1)
const age = resultSet.getColumnName(2)
const id = resultSet.getColumnName(0);
const name = resultSet.getColumnName(1);
const age = resultSet.getColumnName(2);
```
### goTo
goTo(offset:number): boolean
......@@ -106,28 +108,30 @@ 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.|
**Example**
```js
let predicatesgoto = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygoto = rdbStore.query(predicatesgoto, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgoto = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoto = rdbStore.query(predicatesgoto, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoto.then((resultSet) {
resultSet.goTo(1)
resultSet.close()
resultSet.goTo(1);
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### goToRow
goToRow(position: number): boolean
......@@ -137,28 +141,30 @@ Moves the cursor to the specified row in the result set.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| position | number | Yes| Position to which the cursor is to be moved.|
**Return value**
| Type| Description|
| -------- | -------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|
**Example**
```js
let predicatesgotorow = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygotorow = rdbStore.query(predicatesgotorow, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgotorow = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygotorow = rdbStore.query(predicatesgotorow, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygotorow.then((resultSet) {
resultSet.goToRow(5)
resultSet.close()
resultSet.goToRow(5);
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### goToFirstRow
goToFirstRow(): boolean
......@@ -169,23 +175,24 @@ Moves the cursor 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.|
**Example**
```js
let predicatesgoFirst = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygoFirst = rdbStore.query(predicatesgoFirst, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgoFirst = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoFirst = rdbStore.query(predicatesgoFirst, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoFirst.then((resultSet) {
resultSet.goToFirstRow()
resultSet.close()
resultSet.goToFirstRow();
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### goToLastRow
goToLastRow(): boolean
......@@ -195,23 +202,24 @@ Moves the cursor 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.|
**Example**
```js
let predicatesgoLast = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygoLast = rdbStore.query(predicatesgoLast, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgoLast = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoLast = rdbStore.query(predicatesgoLast, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoLast.then((resultSet) {
resultSet.goToLastRow()
resultSet.close()
resultSet.goToLastRow();
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### goToNextRow
goToNextRow(): boolean
......@@ -221,23 +229,24 @@ Moves the cursor 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.|
**Example**
```js
let predicatesgoNext = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygoNext = rdbStore.query(predicatesgoNext, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgoNext = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoNext = rdbStore.query(predicatesgoNext, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoNext.then((resultSet) {
resultSet.goToNextRow()
resultSet.close()
resultSet.goToNextRow();
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### goToPreviousRow
goToPreviousRow(): boolean
......@@ -247,23 +256,24 @@ Moves the cursor 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.|
**Example**
```js
let predicatesgoPrev = new dataRdb.RdbPredicates("EMPLOYEE")
let promisequerygoPrev = rdbStore.query(predicatesgoPrev, ["ID", "NAME", "AGE", "SALARY", "CODES"])
let predicatesgoPrev = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoPrev = rdbStore.query(predicatesgoPrev, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoPrev.then((resultSet) {
resultSet.goToPreviousRow()
resultSet.close()
resultSet.goToPreviousRow();
resultSet.close();
}).catch((err) => {
console.log('query failed')
})
console.log('query failed');
});
```
### getBlob
getBlob(columnIndex: number): Uint8Array
......@@ -273,21 +283,23 @@ Obtains the value in the specified column in the current row as a byte array.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Index of the specified column, starting from 0.|
**Return value**
| Type| Description|
| -------- | -------- |
| Uint8Array | Value in the specified column as a byte array.|
**Example**
```js
const codes = resultSet.getBlob(resultSet.getColumnIndex("CODES"))
const codes = resultSet.getBlob(resultSet.getColumnIndex("CODES"));
```
### getString
getString(columnIndex: number): string
......@@ -297,21 +309,23 @@ Obtains the value in the specified column in the current row as a string.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Index of the specified column, starting from 0.|
**Return value**
| Type| Description|
| -------- | -------- |
| string | Value in the specified column as a string.|
**Example**
```js
const name = resultSet.getString(resultSet.getColumnIndex("NAME"))
const name = resultSet.getString(resultSet.getColumnIndex("NAME"));
```
### getLong
getLong(columnIndex: number): number
......@@ -321,21 +335,23 @@ Obtains the value in the specified column in the current row as a Long.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Index of the specified column, starting from 0.|
**Return value**
| Type| Description|
| -------- | -------- |
| number | Value in the specified column as a Long.|
**Example**
```js
const age = resultSet.getLong(resultSet.getColumnIndex("AGE"))
const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));
```
### getDouble
getDouble(columnIndex: number): number
......@@ -345,21 +361,23 @@ Obtains the value in the specified column in the current row as a double.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Index of the specified column, starting from 0.|
**Return value**
| Type| Description|
| -------- | -------- |
| number | Value in the specified column as a double.|
**Example**
```js
const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"))
const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));
```
### isColumnNull
isColumnNull(columnIndex: number): boolean
......@@ -369,21 +387,23 @@ Checks whether the value in the specified column of the current row is null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| columnIndex | number | Yes| Index of the specified column, starting from 0.|
**Return value**
| Type| Description|
| -------- | -------- |
| boolean | Returns **true** if the value is null; returns **false** otherwise.|
**Example**
```js
const isColumnNull = resultSet.isColumnNull(resultSet.getColumnIndex("CODES"))
const isColumnNull = resultSet.isColumnNull(resultSet.getColumnIndex("CODES"));
```
### close
close(): void
......@@ -393,12 +413,13 @@ 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"])
let predicatesClose = new dataRdb.RdbPredicates("EMPLOYEE");
let promiseClose = rdbStore.query(predicatesClose, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promiseClose.then((resultSet) {
resultSet.close()
resultSet.close();
}).catch((err) => {
console.log('Failed to close resultset')
})
console.log('Failed to close resultset');
});
```
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