@ohos.data.dataShareResultSet (DataShare Result Set) (System API)

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.

The APIs of this module can be used only in the stage model.

The system allows a maximum of 32 data share result sets. Release the data share result sets that are no longer used in a timely manner.

Modules to Import

import { DataShareResultSet } from '@kit.ArkData';

Usage

You can use query to obtain a DataShareResultSet object.

import { DataShareResultSet, dataShare, dataSharePredicates } from '@kit.ArkData';
import { BusinessError } from '@kit.BasicServicesKit'
import { UIAbility } from '@kit.AbilityKit';

let dataShareHelper: dataShare.DataShareHelper|undefined = undefined;
let uri = ("datashare:///com.samples.datasharetest.DataShare");
let context = getContext(UIAbility);
dataShare.createDataShareHelper(context, uri, (err:BusinessError, data:dataShare.DataShareHelper) => {
  if (err != undefined) {
    console.error("createDataShareHelper fail, error message : " + err);
  } else {
    console.info("createDataShareHelper end, data : " + data);
    dataShareHelper = data;
  }
});

let columns = ["*"];
let da = new dataSharePredicates.DataSharePredicates();
let resultSet: DataShareResultSet|undefined = undefined;
da.equalTo("name", "ZhangSan");
if (dataShareHelper != undefined) {
  (dataShareHelper as dataShare.DataShareHelper).query(uri, da, columns).then((data: DataShareResultSet) => {
    console.info("query end, data : " + data);
    resultSet = data;
  }).catch((err: BusinessError) => {
    console.error("query fail, error message : " + err);
  });
}

DataShareResultSet

Provides APIs for accessing the result sets returned.

The column or key names are returned as a string array, in which the strings are in the same order as the columns or keys in the result set.

Properties

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. The value true means the result set is closed; the value false means the opposite.

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

// Create a resultSet object. For details, see Usage in this topic.
if (resultSet != undefined) {
  let isGoToFirstRow = (resultSet as DataShareResultSet).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

if (resultSet != undefined) {
  let isGoToLastRow = (resultSet as DataShareResultSet).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

if (resultSet != undefined) {
  let isGoToNextRow = (resultSet as DataShareResultSet).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

if (resultSet != undefined) {
  let isGoToPreviousRow = (resultSet as DataShareResultSet).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;
if (resultSet != undefined) {
  let isGoTo = (resultSet as DataShareResultSet).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	Position to move to, starting from 0.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let goToRowNum = 2;
if (resultSet != undefined) {
  let isGoToRow = (resultSet as DataShareResultSet).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.

If the specified column or key is empty or the value is not of the Blob type, you need to determine whether to throw an exception.

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;
if (resultSet != undefined) {
  let goToFirstRow = (resultSet as DataShareResultSet).goToFirstRow();
  let getBlob = (resultSet as DataShareResultSet).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.

If the specified column or key is empty or the value is not of the string type, you need to determine whether to throw an exception.

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;
if (resultSet != undefined) {
  let goToFirstRow = (resultSet as DataShareResultSet).goToFirstRow();
  let getString = (resultSet as DataShareResultSet).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.

If the specified column or key is empty or the value is not of the long type, you need to determine whether to throw an exception.

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;
if (resultSet != undefined) {
  let goToFirstRow = (resultSet as DataShareResultSet).goToFirstRow();
  let getLong = (resultSet as DataShareResultSet).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.

If the specified column or key is empty or the value is not of the double type, you need to determine whether to throw an exception.

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;
if (resultSet != undefined) {
  let goToFirstRow = (resultSet as DataShareResultSet).goToFirstRow();
  let getDouble = (resultSet as DataShareResultSet).getDouble(columnIndex);
  console.info('resultSet.getDouble: ' + getDouble);
}

close

close(): void

Closes this result set.

Calling this API will invalidate the result set and release all its resources.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Example

if (resultSet != undefined) {
  (resultSet as DataShareResultSet).close();
}

getColumnIndex

getColumnIndex(columnName: string): number

Obtains the column index based on a column name.

The column name is passed in as an input parameter.

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";
if (resultSet != undefined) {
  let getColumnIndex = (resultSet as DataShareResultSet).getColumnIndex(ColumnName);
  console.info('resultSet.getColumnIndex: ' + getColumnIndex);
}

getColumnName

getColumnName(columnIndex: number): string

Obtains the column name based on a column index.

The column index is passed in as an input parameter.

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;
if (resultSet != undefined) {
  let getColumnName = (resultSet as DataShareResultSet).getColumnName(columnIndex);
  console.info('resultSet.getColumnName: ' + getColumnName);
}

getDataType

getDataType(columnIndex: number): DataType

Obtains the data type based on the specified column index.

If the specified column or key is empty or the value is not of the DataType type, you need to determine whether to throw an exception.

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;
if (resultSet != undefined) {
  let getDataType = (resultSet as DataShareResultSet).getDataType(columnIndex);
  console.info('resultSet.getDataType: ' + getDataType);
}