@ohos.data.dataShareResultSet (DataShare Result Set)
The DataShareResultSet module provides APIs for accessing the result set obtained from the database. You can access the values in the specified rows or the value of the specified data type.
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.
The APIs provided by this module are system APIs.
Modules to Import
import DataShareResultSet from '@ohos.data.DataShareResultSet';
Usage
You can call query() to obtain the DataShareResultSet object.
import dataShare from '@ohos.data.dataShare';
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let dataShareHelper;
let uri = ("datashare:///com.samples.datasharetest.DataShare");
await dataShare.createDataShareHelper(this.context, uri, (err, data) => {
if (err != undefined) {
console.info("createDataShareHelper fail, error message : " + err);
} else {
console.info("createDataShareHelper end, data : " + data);
dataShareHelper = data;
}
});
let columns = ["*"];
let da = new dataSharePredicates.DataSharePredicates();
let resultSet;
da.equalTo("name", "ZhangSan");
dataShareHelper.query(uri, da, columns).then((data) => {
console.log("query end, data : " + data);
resultSet = data;
}).catch((err) => {
console.log("query fail, error message : " + err);
});
DataShareResultSet
Provides methods for accessing the result sets generated by querying the database.
Attributes
System capability: SystemCapability.DistributedDataManager.DataShare.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. |
isClosed | boolean | Yes | Whether the result set is closed. |
goToFirstRow
goToFirstRow(): boolean
Moves to the first row of the result set.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
Example
let isGoTOFirstRow = resultSet.goToFirstRow();
console.info('resultSet.goToFirstRow: ' + isGoTOFirstRow);
goToLastRow
goToLastRow(): boolean
Moves to the last row of the result set.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
Example
let isGoToLastRow = resultSet.goToLastRow();
console.info('resultSet.goToLastRow: ' + isGoToLastRow);
goToNextRow
goToNextRow(): boolean
Moves to the next row in the result set.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
Example
let isGoToNextRow = resultSet.goToNextRow();
console.info('resultSet.goToNextRow: ' + isGoToNextRow);
goToPreviousRow
goToPreviousRow(): boolean
Moves to the previous row in the result set.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
Example
let isGoToPreviousRow = resultSet.goToPreviousRow();
console.info('resultSet.goToPreviousRow: ' + isGoToPreviousRow);
goTo
goTo(offset:number): boolean
Moves based on the specified offset.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
offset | number | Yes | Offset relative to the current position. A negative value means to move backward, and a positive value means to move forward. |
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
Example
let goToNum = 1;
let isGoTo = resultSet.goTo(goToNum);
console.info('resultSet.goTo: ' + isGoTo);
goToRow
goToRow(position: number): boolean
Moves to the specified row in the result set.
System capability: SystemCapability.DistributedDataManager.DataShare.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. |
Example
let goToRowNum = 2;
let isGoToRow = resultSet.goToRow(goToRowNum);
console.info('resultSet.goToRow: ' + isGoToRow);
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.DataShare.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
let columnIndex = 1;
let goToFirstRow = resultSet.goToFirstRow();
let getBlob = resultSet.getBlob(columnIndex);
console.info('resultSet.getBlob: ' + getBlob);
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.DataShare.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
columnIndex | number | Yes | Index of the target column, starting from 0. |
Return value
Type | Description |
---|---|
string | Value obtained. |
Example
let columnIndex = 1;
let goToFirstRow = resultSet.goToFirstRow();
let getString = resultSet.getString(columnIndex);
console.info('resultSet.getString: ' + getString);
getLong
getLong(columnIndex: number): number
Obtains the value in the form of a long integer based on the specified column and the current row.
System capability: SystemCapability.DistributedDataManager.DataShare.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
let columnIndex = 1;
let goToFirstRow = resultSet.goToFirstRow();
let getLong = resultSet.getLong(columnIndex);
console.info('resultSet.getLong: ' + getLong);
getDouble
getDouble(columnIndex: number): number
Obtains the value in the form of a double-precision floating-point number based on the specified column and the current row.
System capability: SystemCapability.DistributedDataManager.DataShare.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
let columnIndex = 1;
let goToFirstRow = resultSet.goToFirstRow();
let getDouble = resultSet.getDouble(columnIndex);
console.info('resultSet.getDouble: ' + getDouble);
close
close(): void
Closes this result set.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Example
resultSet.close();
getColumnIndex
getColumnIndex(columnName: string): number
Obtains the column index based on the column name.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
columnName | string | Yes | Column name. |
Return value
Type | Description |
---|---|
number | Column index obtained. |
Example
let ColumnName = "name";
let getColumnIndex = resultSet.getColumnIndex(ColumnName);
console.info('resultSet.getColumnIndex: ' + getColumnIndex);
getColumnName
getColumnName(columnIndex: number): string
Obtains the column name based on the column index.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
columnIndex | number | Yes | Column index. |
Return value
Type | Description |
---|---|
string | Column name obtained. |
Example
let columnIndex = 1;
let getColumnName = resultSet.getColumnName(columnIndex);
console.info('resultSet.getColumnName: ' + getColumnName);
getDataType
getDataType(columnIndex: number): DataType
Obtains the data type based on the specified column index.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
columnIndex | number | Yes | Column index. |
Return value
Type | Description |
---|---|
DataType | Data type obtained. |
Example
let columnIndex = 1;
let getDataType = resultSet.getDataType(columnIndex);
console.info('resultSet.getDataType: ' + getDataType);
DataType
Enumerates the data types.
System capability: SystemCapability.DistributedDataManager.DataShare.Core
Name | Value | Description |
---|---|---|
TYPE_NULL | 0 | Null. |
TYPE_LONG | 1 | Long integer. |
TYPE_DOUBLE | 2 | Double-precision floating-point number. |
TYPE_STRING | 3 | String. |
TYPE_BLOB | 4 | Byte array. |