resultSet

A result set is a set of results returned after the relational database (RDB) query APIs are called. You can use the resultset APIs to obtain required data.

NOTE

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The APIs of this module are no longer maintained since API version 9. You are advised to use @ohos.data.relationalStore#ResultSet.

ResultSet

Provides methods to access the result set, which is obtained by querying the RDB store.

Usage

You need to obtain a resultSet object by using RdbStore.query().

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 specified.

Return value

Type	Description
number	Index of the column obtained.

Example

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 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

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.

Example

let predicatesgoto = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoto = rdbStore.query(predicatesgoto, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoto.then((resultSet) => {
    resultSet.goTo(1);
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

goToRow

goToRow(position: number): boolean

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

let predicatesgotorow = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygotorow = rdbStore.query(predicatesgotorow, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygotorow.then((resultSet) => {
    resultSet.goToRow(5);
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

goToFirstRow

goToFirstRow(): boolean

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

let predicatesgoFirst = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoFirst = rdbStore.query(predicatesgoFirst, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoFirst.then((resultSet) => {
    resultSet.goToFirstRow();
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

goToLastRow

goToLastRow(): boolean

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

let predicatesgoLast = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoLast = rdbStore.query(predicatesgoLast, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoLast.then((resultSet) => {
    resultSet.goToLastRow();
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

goToNextRow

goToNextRow(): boolean

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

let predicatesgoNext = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoNext = rdbStore.query(predicatesgoNext, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoNext.then((resultSet) => {
    resultSet.goToNextRow();
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

goToPreviousRow

goToPreviousRow(): boolean

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

let predicatesgoPrev = new dataRdb.RdbPredicates("EMPLOYEE");
let promisequerygoPrev = rdbStore.query(predicatesgoPrev, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promisequerygoPrev.then((resultSet) => {
    resultSet.goToPreviousRow();
    resultSet.close();
}).catch((err) => {
    console.log('query failed');
});

getBlob

getBlob(columnIndex: number): Uint8Array

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

const codes = resultSet.getBlob(resultSet.getColumnIndex("CODES"));

getString

getString(columnIndex: number): string

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

const name = resultSet.getString(resultSet.getColumnIndex("NAME"));

getLong

getLong(columnIndex: number): number

Obtains the value in the specified column in the current row as a Long integer.

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 integer. The value range supported by this API is Number.MIN_SAFE_INTEGER to Number.MAX_SAFE_INTEGER. If the value is out of this range, use getDouble.

Example

const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));

getDouble

getDouble(columnIndex: number): number

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

const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));

isColumnNull

isColumnNull(columnIndex: number): boolean

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

const isColumnNull = resultSet.isColumnNull(resultSet.getColumnIndex("CODES"));

close

close(): void

Closes this result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

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('Failed to close the resultset');
});

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