diff --git a/en/application-dev/reference/apis/js-apis-data-resultset.md b/en/application-dev/reference/apis/js-apis-data-resultset.md index 3098499d48ca52b0251cfb9648cc032fc26e2652..28cde770498760d5eac09dc79c5b495f91d05c4a 100644 --- a/en/application-dev/reference/apis/js-apis-data-resultset.md +++ b/en/application-dev/reference/apis/js-apis-data-resultset.md @@ -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'); + }); ```