5dfe75c5创建于 2月13日历史提交

Class (LiteResultSet)

Defines APIs to access the result set obtained by querying the RDB store. This result set is the collection of results returned with the query() method called.

The LiteResultSet instance is not refreshed in real time. After using the result set, if the data in the database is changed (by being added, deleted, or modified), you need to query the result set again to obtain the latest data.

In the following API examples, you need to obtain an LiteResultSet instance by using a query method, such as queryWithoutRowCount or querySqlWithoutRowCount, and then call the corresponding method through this instance.

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 initial APIs of this class are supported since API version 23.

Module to Import

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

getColumnNames²³⁺

getColumnNames(): Array<string>

Obtains the names of all columns in the result set.

The column names are returned in a string array. The sequence of strings in the array is the same as that of columns in the result set.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
Array<string>	Names of all columns in the result set obtained. Duplicate column names can be obtained.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1. Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getColumnNamesExample(store : relationalStore.RdbStore){
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    // Query EMPLOYEE1 and EMPLOYEE2 and obtain the duplicate column names. store is the obtained RdbStore instance.
    resultSet = await store.querySqlWithoutRowCount("SELECT e1.NAME, e2.NAME, e1.AGE, e2.AGE FROM EMPLOYEE1 e1 LEFT JOIN EMPLOYEE2 e2 ON e1.SALARY=e2.SALARY");
    if (resultSet != undefined) {
      const names = resultSet.getColumnNames();
    }
  } catch (err) {
    console.error(`Failed to get column names: code:${err.code}, message:${err.message}`);
  }
}

getColumnIndex²³⁺

getColumnIndex(columnName: string): number

Obtains the column index based on the column name.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnName	string	Yes	Column name. If the result set contains duplicate column names, the return value is not as expected.

Return value

Type	Description
number	Column index obtained.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getColumnIndexExample(store : relationalStore.RdbStore){
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      const idIndex = resultSet.getColumnIndex("ID");
      const nameIndex = resultSet.getColumnIndex("NAME");
      const ageIndex = resultSet.getColumnIndex("AGE");
      const salaryIndex = resultSet.getColumnIndex("SALARY");
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getColumnName²³⁺

getColumnName(columnIndex: number): string

Obtains the column name based on the column index.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the column in the result set, starting from 0.

Return value

Type	Description
string	Column name obtained. If the result set contains duplicate column names, the return value is not as expected.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getColumnNameExample(store : relationalStore.RdbStore){
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      const id = resultSet.getColumnName(0);
      const name = resultSet.getColumnName(1);
      const age = resultSet.getColumnName(2);
      const salary = resultSet.getColumnName(3);
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getColumnType²³⁺

getColumnType(columnIdentifier: number | string): Promise<ColumnType>

Obtains the column type based on the specified column index or column name. This API uses a promise to return the result.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIdentifier	number \| string	Yes	Index or name of the column in the result set. The index starts from 0.

Return value

Type	Description
Promise<ColumnType>	Promise used to return the column type obtained. If the result set contains duplicate column names, the return value is not as expected.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getColumnTypeExample(store : relationalStore.RdbStore){
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      //Method 1: Obtain the column type by column name.
      let idType = await resultSet.getColumnType("ID");
      let nameType = await resultSet.getColumnType("NAME");
      let ageType = await resultSet.getColumnType("AGE");
      let salaryType = await resultSet.getColumnType("SALARY");
      let codesType = await resultSet.getColumnType("CODES");
      //Method 2: Obtain the column type by column index.
      let identityType = await resultSet.getColumnType(5);
      let assetDataType = await resultSet.getColumnType(6);
      let assetsDataType = await resultSet.getColumnType(7);
      let floatArrayType = await resultSet.getColumnType(8);
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getColumnTypeSync²³⁺

getColumnTypeSync(columnIdentifier: number | string): ColumnType

Obtains the column type based on the specified column index or column name.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIdentifier	number \| string	Yes	Index or name of the column in the result set. The index starts from 0.

Return value

Type	Description
ColumnType	Column type obtained. If the result set contains duplicate column names, the return value is not as expected.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getColumnTypeSyncExample(store : relationalStore.RdbStore){
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      //Method 1: Obtain the column type by column name.
      let idType = resultSet.getColumnTypeSync("ID");
      let nameType = resultSet.getColumnTypeSync("NAME");
      let ageType = resultSet.getColumnTypeSync("AGE");
      let salaryType = resultSet.getColumnTypeSync("SALARY");
      let codesType = resultSet.getColumnTypeSync("CODES");
      //Method 2: Obtain the column type by column index.
      let identityType = resultSet.getColumnTypeSync(5);
      let assetDataType = resultSet.getColumnTypeSync(6);
      let assetsDataType = resultSet.getColumnTypeSync(7);
      let floatArrayType = resultSet.getColumnTypeSync(8);
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

goToNextRow²³⁺

goToNextRow(): boolean

Moves the result set to the next row.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
boolean	Returns true if the result set is successfully moved to the next row; returns false otherwise.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.
14800031	SQLite: TEXT or BLOB exceeds size limit.

Example:

async function goToNextRowExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getValue²³⁺

getValue(columnIndex: number): ValueType

Obtains the value of the specified column in the current row.

If the value type is INTEGER and the value is greater than Number.MAX_SAFE_INTEGER or less than Number.MIN_SAFE_INTEGER, you are advised to use the getString API to obtain the value without precision loss.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
ValueType	Type of the data field returned.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.

Example:

async function getValueExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const name = resultSet.getValue(resultSet.getColumnIndex("NAME"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getBlob²³⁺

getBlob(columnIndex: number): Uint8Array

Obtains the value in the specified column in the current row as a byte array.

If the data type of the current column is INTEGER, DOUBLE, TEXT, or BLOB, the data is converted to a byte array and returned. If the content of the column is null/empty, an empty byte array is returned.
If the data type of the current column is ASSET, ASSETS, FLOATVECTOR, or BIGINT, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
Uint8Array	Value obtained.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getBlobExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const name = resultSet.getBlob(resultSet.getColumnIndex("CODES"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getString²³⁺

getString(columnIndex: number): string

Obtains the value in the specified column in the current row as a string.

If the data type of the current column is INTEGER, DOUBLE, TEXT, or BLOB type, the value is returned as a string. If the content of the column is null/empty, an empty string "" is returned.
If the data type of the current column is DOUBLE, precision loss may occur. You are advised to use getDouble API to obtain the value.
If the data type of the current column is ASSET, ASSETS, FLOATVECTOR, or BIGINT, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
string	Value obtained.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getStringExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const name = resultSet.getString(resultSet.getColumnIndex("NAME"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getLong²³⁺

getLong(columnIndex: number): number

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

If the data type of the current column is INTEGER, DOUBLE, or TEXT, the value is converted to the Long type and returned. Non-numeric TEXT and BLOB types return 0. If the column is null/empty, 0 is returned.
If the data type of the current column is INTEGER and the value is greater than Number.MAX_SAFE_INTEGER or less than Number.MIN_SAFE_INTEGER, you are advised to use the getString API to obtain the value without precision loss.
If the data type of the current column is DOUBLE, you are advised to use the getDouble API to obtain the value without precision loss.
If the data type of the current column is ASSET, ASSETS, FLOATVECTOR, or BIGINT, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
number	Value obtained. 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 for DOUBLE values and getString for INTEGER values.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getLongExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getDouble²³⁺

getDouble(columnIndex: number): number

Obtains the value in the specified column in the current row as a Double.

If the data type of the current column is INTEGER, DOUBLE, or TEXT, the value is converted to the Double type and returned. Non-numeric TEXT and BLOB types return 0.0. If the content of the column is null/empty, 0.0 is returned.
If the data type of the current column is ASSET, ASSETS, FLOATVECTOR, or BIGINT, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
number	Value obtained.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getDoubleExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getAsset²³⁺

getAsset(columnIndex: number): Asset

Obtains the value in the specified column in the current row as an Asset.

If the data type of the current column is Asset, the value is returned as an Asset. If the value in the current column is null, null is returned. If the data type of the current column is not Asset, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
Asset	Value obtained.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getAssetExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const doc = resultSet.getAsset(resultSet.getColumnIndex("DOC"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getAssets²³⁺

getAssets(columnIndex: number): Assets

Obtains the value in the specified column in the current row as Assets.

If the data type of the current column is Assets, the value is returned as Assets. If the value in the current column is null, null is returned. If the data type of the current column is not Assets, 14800041 is returned.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
Assets	Value obtained.

Error codes

For details about the error codes, see RDB Error Codes.

ID	Error Message
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800041	Type conversion failed.

Example:

async function getAssetsExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const name = resultSet.getAssets(resultSet.getColumnIndex("DOCS"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getRow²³⁺

getRow(): ValuesBucket

Obtains data for the current row.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
ValuesBucket	Value of the specified row. If the result set contains duplicate column names, the return value is not as expected. You are advised to use the getCurrentRowData API.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getRowExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const rowData = resultSet.getRow();
      console.info(`rowData: ${JSON.stringify(rowData)}`);
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getCurrentRowData²³⁺

getCurrentRowData(): RowData

Obtains the values of all columns in this row.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RowData	Values of all columns in this row obtained. The values of columns with the same name can be obtained.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1. Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function getCurrentRowDataExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    // Query EMPLOYEE1 and EMPLOYEE2 and obtain the values of the current row that contain duplicate column names. store is the obtained RdbStore instance.
    resultSet = await store.querySqlWithoutRowCount("SELECT e1.NAME, e2.NAME, e1.AGE, e2.AGE FROM EMPLOYEE1 e1 LEFT JOIN EMPLOYEE2 e2 ON e1.SALARY=e2.SALARY");
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const rowData = resultSet.getCurrentRowData();
      console.info(`rowData: ${JSON.stringify(rowData)}`);
    }
  } catch (err) {
    console.error(`Failed to get row data: code:${err.code}, message:${err.message}`);
  }
}

getRows²³⁺

getRows(maxCount: number, position?: number): Promise<Array<ValuesBucket>>

Obtains a specified amount of data from the result set. This API uses a promise to return the result. Do not call this API concurrently with other APIs of LiteResultSet. Otherwise, unexpected data may be obtained.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
maxCount	number	Yes	Number of rows to obtain. The value is a positive integer.
position	number	No	Start position for obtaining data from the result set. The value is a non-negative integer. If this parameter is not specified, data is obtained from the current row of the result set (by default, it is the first row of the result set when data is obtained for the first time).

Return value

Type	Description
Promise<Array<ValuesBucket>>	Promise used to return maxCount rows of data obtained. If the number of remaining records is less than maxCount, the remaining records are returned. Returning an empty array indicates that the end of the result set is reached. If the result set contains duplicate column names, the return values are not as expected. You are advised to use the getRowsData API.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.
14800031	SQLite: TEXT or BLOB exceeds size limit.

Example:

async function getRowsExample(store : relationalStore.RdbStore) {
  // Obtain 100 rows of data.
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    // Example 1: Specify only maxCount.
    if (resultSet != undefined) {
      let rows: Array<relationalStore.ValuesBucket>;
      let maxCount: number = 50;
      // Obtain data from the current row of the result set. By default, the first fetch starts from the first row of the current result set. Subsequent fetches start from the row following the last row retrieved.
      // getRows automatically moves the current row of the result set to the next row after the end position of the last retrieval by getRows. You do not need to use the goToNextRow API to move the row.
      while ((rows = await resultSet.getRows(maxCount)).length != 0) {
        console.info(JSON.stringify(rows[0]));
      }
    }
  
    // Example 2: Specify maxCount and position.
    if (resultSet != undefined) {
      let rows: Array<relationalStore.ValuesBucket>;
      let maxCount: number = 50;
      let position: number = 50;
      while ((rows = await resultSet.getRows(maxCount, position)).length != 0) {
        console.info(JSON.stringify(rows[0]));
        position += rows.length;
      }
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

getRowsData²³⁺

getRowsData(maxCount: number, position?: number): Promise<RowsData>

Obtains data of a specified number of rows from the specified position. This API uses a promise to return the result. Do not call this API concurrently with other APIs of LiteResultSet. Otherwise, unexpected data may be obtained.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
maxCount	number	Yes	Number of rows to obtain. The value is a positive integer. If the value is not a positive integer, error 14800001 will be thrown.
position	number	No	Start position for obtaining data from the result set. The value is a non-negative integer. If this parameter is not specified, data is obtained from the current row of the result set (by default, it is the first row of the result set when data is obtained for the first time). If the value is not a non-negative integer, error code 14800001 will be thrown.

Return value

Type	Description
Promise<RowsData>	Promise used to return maxCount rows of data obtained. If the number of remaining records is less than maxCount, the remaining records are returned. Returning an empty array indicates that the end of the result set is reached. The values of columns with the same name can be obtained.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1. Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.
14800031	SQLite: TEXT or BLOB exceeds size limit.

Example:

async function getRowsDataExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    // Query EMPLOYEE1 and EMPLOYEE2 and obtain the values of multiple rows that contain duplicate column names. store is the obtained RdbStore instance.
    resultSet = await store.querySqlWithoutRowCount("SELECT e1.NAME, e2.NAME, e1.AGE, e2.AGE FROM EMPLOYEE1 e1 LEFT JOIN EMPLOYEE2 e2 ON e1.SALARY=e2.SALARY");
    // Obtain 50 rows of data.
    // Example 1: Specify only maxCount.
    if (resultSet != undefined) {
      let rowsData: relationalStore.RowsData;
      // Obtain data from the current row of the result set. By default, the first fetch starts from the first row of the current result set. Subsequent fetches start from the row following the last row retrieved.
      // getRowsData automatically moves the current row of the result set to the next row after the end position of the last retrieval by getRowsData. You do not need to use the goToNextRow API to move the row.
      let maxCount: number = 50;
      let rowCount: number = 0;
      while ((rowsData = await resultSet.getRowsData(maxCount)).length != 0) {
        rowsData.forEach((rowData, index) => {
          // Query result of the row specified by rowCount + index + 1
          console.info(`${rowCount + index + 1}: ${rowData}`);
        });
        rowCount += rowsData.length;
      }
    }
  
    // Example 2: Specify maxCount and position.
    if (resultSet != undefined) {
      let rowsData: relationalStore.RowsData;
      let maxCount: number = 50;
      let position: number = 50;
      while ((rowsData = await resultSet.getRowsData(maxCount, position)).length != 0) {
        rowsData.forEach((rowData, index) => {
          // Query result of the row specified by position + index + 1
          console.info(`${position + index + 1}: ${rowData}`);
        });
        position += rowsData.length;
      }
    }
  } catch (err) {
    console.error(`Failed to get rows data: code:${err.code}, message:${err.message}`);
  }
}

isColumnNull²³⁺

isColumnNull(columnIndex: number): boolean

Checks whether the value in the specified column is null.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
columnIndex	number	Yes	Index of the target column, starting from 0.

Return value

Type	Description
boolean	Returns true if the value is null; returns false otherwise.

Error codes

For details about the error codes, see RDB Error Codes. For details about how to handle error 14800011, see Database Backup and Restore.

ID	Error Message
14800001	Invalid arguments. Possible causes: 1.Parameter is out of valid range.
14800011	The current operation failed because the database is corrupted.
14800012	ResultSet is empty or pointer index is out of bounds.
14800013	Column index is out of bounds.
14800014	The target instance is already closed.
14800019	The SQL must be a query statement.
14800021	SQLite: Generic error. Possible causes: Insert failed or the updated data does not exist.
14800026	SQLite: The database is out of memory.
14800028	SQLite: Some kind of disk I/O error occurred.
14800030	SQLite: Unable to open the database file.

Example:

async function isColumnNullExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.goToNextRow();
      const name = resultSet.isColumnNull(resultSet.getColumnIndex("NAME"));
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

close²³⁺

close(): void

Closes this resultSet to release memory. If the resultSet is not closed, FD or memory leaks may occur.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example:

async function closeExample(store : relationalStore.RdbStore) {
  try {
    let resultSet: relationalStore.LiteResultSet | undefined;
    resultSet = await store.querySqlWithoutRowCount('select * from EMPLOYEE where name = ?', ["Rose"]);
    if (resultSet != undefined) {
      resultSet.close();
    }
  } catch (err) {
    console.error(`failed, code is ${err.code}, message is ${err.message}`);
  }
}

Class (LiteResultSet)

Module to Import

getColumnNames23+

getColumnIndex23+

getColumnName23+

getColumnType23+

getColumnTypeSync23+

goToNextRow23+

getValue23+

getBlob23+

getString23+

getLong23+

getDouble23+

getAsset23+

getAssets23+

getRow23+

getCurrentRowData23+

getRows23+

getRowsData23+

isColumnNull23+

close23+

getColumnNames²³⁺

getColumnIndex²³⁺

getColumnName²³⁺

getColumnType²³⁺

getColumnTypeSync²³⁺

goToNextRow²³⁺

getValue²³⁺

getBlob²³⁺

getString²³⁺

getLong²³⁺

getDouble²³⁺

getAsset²³⁺

getAssets²³⁺

getRow²³⁺

getCurrentRowData²³⁺

getRows²³⁺

getRowsData²³⁺

isColumnNull²³⁺

close²³⁺