ResultSet

所有已知子接口:

SharedResultSet

所有已知实现类:

AbsResultSet, AbsSharedResultSet, CombinedResultSet, ResultSetWrapper, TableResultSet
```
public interface ResultSet
```
Provides methods for accessing a database result set generated by querying the database.
The abstract class AbsResultSet implements some methods in the ResultSet interface.

从以下版本开始:

1

另请参阅:

AbsResultSet

SystemCapability

SystemCapability.Data#DATA_APPDATAMGR

嵌套类概要

嵌套类
限定符和类型接口说明

static class ResultSet.ColumnType
Defines the data types of columns in the result set.

嵌套类
限定符和类型	接口	说明
`static class`	`ResultSet.ColumnType`	Defines the data types of columns in the result set.

方法概要

所有方法实例方法抽象方法
限定符和类型	方法	说明
`void`	`close()`	Closes the result set.
`List<Uri>`	`getAffectedByUris()`	Obtains the list of URIs registered to observe changes that affect the result set.
`String[]`	`getAllColumnNames()`	Obtains the names of all columns in a result set.
`byte[]`	`getBlob(int columnIndex)`	Obtains the value of the specified column in the current row as a byte array.
`int`	`getColumnCount()`	Obtains the number of columns in the result set.
`int`	`getColumnIndexForName(String columnName)`	Obtains the column index based on the specified column name.
`String`	`getColumnNameForIndex(int columnIndex)`	Obtains the column name based on the specified column index.
`ResultSet.ColumnType`	`getColumnTypeForIndex(int columnIndex)`	Obtains the data type based on the specified column index.
`double`	`getDouble(int columnIndex)`	Obtains the value of the specified column in the current row as a double.
`PacMap`	`getExtensions()`	Obtains extensions of the result set.
`float`	`getFloat(int columnIndex)`	Obtains the value of the specified column in the current row as a float.
`int`	`getInt(int columnIndex)`	Obtains the value of the specified column in the current row as an int.
`long`	`getLong(int columnIndex)`	Obtains the value of the specified column in the current row as a long.
`int`	`getRowCount()`	Obtains the number of rows in the result set.
`int`	`getRowIndex()`	Obtains the current index of the result set.
`short`	`getShort(int columnIndex)`	Obtains the value of the specified column in the current row as a short.
`String`	`getString(int columnIndex)`	Obtains the value of the specified column in the current row as a string.
`boolean`	`goTo(int offset)`	Go to the specified row of the result set forwards or backwards by an offset relative to its current position.
`boolean`	`goToFirstRow()`	Go to the first row of the result set.
`boolean`	`goToLastRow()`	Go to the last row of the result set.
`boolean`	`goToNextRow()`	Go to the next row of the result set.
`boolean`	`goToPreviousRow()`	Go to the previous row of the result set.
`boolean`	`goToRow(int rowIndex)`	Go to the specified row of the result set.
`boolean`	`isAtFirstRow()`	Checks whether the result set is positioned at the first row.
`boolean`	`isAtLastRow()`	Checks whether the result set is positioned at the last row.
`boolean`	`isClosed()`	Checks whether the current result set is closed.
`boolean`	`isColumnNull(int columnIndex)`	Checks whether the value of the specified column in the current row is null.
`boolean`	`isEnded()`	Checks whether the result set is positioned after the last row.
`boolean`	`isStarted()`	Checks whether a result set has been moved.
`void`	`registerObserver(DataObserver observer)`	Registers an observer that listens for data changes.
`void`	`setAffectedByUris(Object context, List<Uri> uris)`	Sets the URIs of the data to be observed.
`void`	`setExtensions(PacMap extensions)`	Sets extensions of the result set.
`void`	`unregisterObserver(DataObserver observer)`	Deregisters an observer that listens for data changes.

- 方法详细资料
  - getAllColumnNames
```
String[] getAllColumnNames()
```
    Obtains the names of all columns in a result set.
    The column names are returned as a string array, in which the strings are in the same order as the columns in the result set.
    
    返回:
    
    Returns a string array containing all the column names in the result set.
    
    从以下版本开始:
    
    1
  - getColumnCount
```
int getColumnCount()
```
    Obtains the number of columns in the result set.
    The returned number is equal to the length of the string array returned by the getAllColumnNames method.
    
    返回:
    
    Returns the number of columns in the result set.
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    getAllColumnNames()
  - getColumnTypeForIndex
```
ResultSet.ColumnType getColumnTypeForIndex(int columnIndex)
```
    Obtains the data type based on the specified column index.
    The return value is of the enumeration type, which can be an integer, float, String, Blob, or null.
    
    参数:
    
    columnIndex - Indicates the specified column index.
    
    返回:
    
    Returns the data type of the specified column.
    
    从以下版本开始:
    
    1
  - getColumnIndexForName
```
int getColumnIndexForName(String columnName)
```
    Obtains the column index based on the specified column name.
    The column name is passed as an input parameter.
    
    参数:
    
    columnName - Indicates the name of the specified column in the result set.
    
    返回:
    
    Returns the index of the specified column.
    
    从以下版本开始:
    
    1
  - getColumnNameForIndex
```
String getColumnNameForIndex(int columnIndex)
```
    Obtains the column name based on the specified column index.
    The column index is passed as an input parameter.
    
    参数:
    
    columnIndex - Indicates the index of the specified column in the result set.
    
    返回:
    
    Returns the name of the specified column.
    
    从以下版本开始:
    
    1
  - getRowCount
```
int getRowCount()
```
    Obtains the number of rows in the result set.
    
    返回:
    
    Returns the number of rows in the result set.
    
    从以下版本开始:
    
    1
  - getRowIndex
```
int getRowIndex()
```
    Obtains the current index of the result set.
    The result set index starts from 0.
    
    返回:
    
    Returns the current index of the result set.
    
    从以下版本开始:
    
    1
  - goTo
```
boolean goTo(int offset)
```
    Go to the specified row of the result set forwards or backwards by an offset relative to its current position. A positive offset indicates moving backwards, and a negative offset indicates moving forwards.
    
    参数:
    
    offset - Indicates the offset relative to the current position.
    
    返回:
    
    Returns true if the result set is moved successfully and does not go beyond the range; returns false otherwise.
    
    从以下版本开始:
    
    1
  - goToRow
```
boolean goToRow(int rowIndex)
```
    Go to the specified row of the result set.
    
    参数:
    
    rowIndex - Indicates the index of the specified row, which starts from 0.
    
    返回:
    
    Returns true if the result set is moved successfully; returns false otherwise.
    
    从以下版本开始:
    
    1
  - goToFirstRow
```
boolean goToFirstRow()
```
    Go to the first row of the result set.
    
    返回:
    
    Returns true if the result set is moved successfully; returns false otherwise, for example, if the result set is empty.
    
    从以下版本开始:
    
    1
  - goToLastRow
```
boolean goToLastRow()
```
    Go to the last row of the result set.
    
    返回:
    
    Returns true if the result set is moved successfully; returns false otherwise, for example, if the result set is empty.
    
    从以下版本开始:
    
    1
  - goToNextRow
```
boolean goToNextRow()
```
    Go to the next row of the result set.
    
    返回:
    
    Returns true if the result set is moved successfully; returns false otherwise, for example, if the result set is already in the last row.
    
    从以下版本开始:
    
    1
  - goToPreviousRow
```
boolean goToPreviousRow()
```
    Go to the previous row of the result set.
    
    返回:
    
    Returns true if the result set is moved successfully; returns false otherwise, for example, if the result set is already in the first row.
    
    从以下版本开始:
    
    1
  - isEnded
```
boolean isEnded()
```
    Checks whether the result set is positioned after the last row.
    
    返回:
    
    Returns true if the result set is positioned after the last row; returns false otherwise.
    
    从以下版本开始:
    
    1
  - isStarted
```
boolean isStarted()
```
    Checks whether a result set has been moved.
    
    返回:
    
    Returns true if the result set has been moved; returns false if the result set has not been moved or the result set is empty.
    
    从以下版本开始:
    
    1
  - isAtFirstRow
```
boolean isAtFirstRow()
```
    Checks whether the result set is positioned at the first row.
    
    返回:
    
    Returns true if the result set is positioned at the first row; returns false otherwise.
    
    从以下版本开始:
    
    1
  - isAtLastRow
```
boolean isAtLastRow()
```
    Checks whether the result set is positioned at the last row.
    
    返回:
    
    Returns true if the result set is positioned at the last row; returns false otherwise.
    
    从以下版本开始:
    
    1
  - getBlob
```
byte[] getBlob(int columnIndex)
```
    Obtains the value of the specified column in the current row as a byte array.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null or the specified column is not of the Blob type.
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a byte array.
    
    从以下版本开始:
    
    1
  - getString
```
String getString(int columnIndex)
```
    Obtains the value of the specified column in the current row as a string.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null or the specified column is not of the string type.
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a string.
    
    从以下版本开始:
    
    1
  - getShort
```
short getShort(int columnIndex)
```
    Obtains the value of the specified column in the current row as a short.
    he implementation class determines whether to throw an exception if the value of the specified column in the current row is null, the specified column is not of the integer type, or the integer is beyond the range [Short.MIN_VALUE, Short.MAX_VALUE].
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a short.
    
    从以下版本开始:
    
    1
  - getInt
```
int getInt(int columnIndex)
```
    Obtains the value of the specified column in the current row as an int.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null, the specified column is not of the integer type, or the integer is beyond the range [Integer.MIN_VALUE, Integer.MAX_VALUE].
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as an int.
    
    从以下版本开始:
    
    1
  - getLong
```
long getLong(int columnIndex)
```
    Obtains the value of the specified column in the current row as a long.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null, the specified column is not of the integer type, or the integer is beyond the range [Long.MIN_VALUE, Long.MAX_VALUE].
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a long.
    
    从以下版本开始:
    
    1
  - getFloat
```
float getFloat(int columnIndex)
```
    Obtains the value of the specified column in the current row as a float.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null, the specified column is not of the floating-point type, or the floating-point value cannot be represented by a float.
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a float.
    
    从以下版本开始:
    
    1
  - getDouble
```
double getDouble(int columnIndex)
```
    Obtains the value of the specified column in the current row as a double.
    The implementation class determines whether to throw an exception if the value of the specified column in the current row is null, the specified column is not of the floating-point type, or the floating-point value cannot be represented by a double.
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns the value of the specified column as a double.
    
    从以下版本开始:
    
    1
  - isColumnNull
```
boolean isColumnNull(int columnIndex)
```
    Checks whether the value of the specified column in the current row is null.
    
    参数:
    
    columnIndex - Indicates the specified column index, which starts from 0.
    
    返回:
    
    Returns true if the value of the specified column in the current row is null; returns false otherwise.
    
    从以下版本开始:
    
    1
  - isClosed
```
boolean isClosed()
```
    Checks whether the current result set is closed.
    If the result set is closed by calling the close method, true will be returned.
    
    返回:
    
    Returns true if the result set is closed; returns false otherwise.
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    close()
  - close
```
void close()
```
    Closes the result set.
    Calling this method on the result set will release all of its resources and makes it ineffective.
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    isClosed()
  - setExtensions
```
void setExtensions(PacMap extensions)
```
    Sets extensions of the result set.
    You can set extensions based on your service requirements.
    
    参数:
    
    extensions - Indicates the extensions to set.
    
    从以下版本开始:
    
    2
    
    另请参阅:
    
    getExtensions()
  - getExtensions
```
PacMap getExtensions()
```
    Obtains extensions of the result set.
    The extensions you will obtain are those set based on your service requirements.
    
    返回:
    
    Returns the extensions of the result set.
    
    从以下版本开始:
    
    2
    
    另请参阅:
    
    setExtensions(ohos.utils.PacMap)
  - setAffectedByUris
```
void setAffectedByUris(Object context,
                       List<Uri> uris)
```
    Sets the URIs of the data to be observed.
    After setting the URIs, call the ResultSet#registerObserver method to register an observer that listens for data changes.
    
    参数:
    
    context - Indicates the context.
    
    uris - Uri list to observe changes which affect this ResultSet.
    
    从以下版本开始:
    
    2
    
    另请参阅:
    
    registerObserver(ohos.data.rdb.DataObserver)
  - getAffectedByUris
```
List<Uri> getAffectedByUris()
```
    Obtains the list of URIs registered to observe changes that affect the result set.
    The list of URIs is set using the ResultSet#setAffectedByUris method.
    
    返回:
    
    Returns the list of URIs.
    
    从以下版本开始:
    
    3
  - registerObserver
```
void registerObserver(DataObserver observer)
```
    Registers an observer that listens for data changes.
    When a notification of the change of data with a specified URI is received, this observer will be triggered.
    
    参数:
    
    observer - Indicates the observer to be registered.
    
    从以下版本开始:
    
    2
    
    另请参阅:
    
    setAffectedByUris(java.lang.Object, java.util.List<ohos.utils.net.Uri>), unregisterObserver(ohos.data.rdb.DataObserver)
  - unregisterObserver
```
void unregisterObserver(DataObserver observer)
```
    Deregisters an observer that listens for data changes.
    This method is used to release the observer before the component to which the observer belongs is destroyed.
    
    参数:
    
    observer - Indicates the observer to be deregistered.
    
    从以下版本开始:
    
    2

接口 ResultSet

嵌套类概要

方法概要

方法详细资料

getAllColumnNames

getColumnCount

getColumnTypeForIndex

getColumnIndexForName

getColumnNameForIndex

getRowCount

getRowIndex

goTo

goToRow

goToFirstRow

goToLastRow

goToNextRow

goToPreviousRow

isEnded

isStarted

isAtFirstRow

isAtLastRow

getBlob

getString

getShort

getInt

getLong

getFloat

getDouble

isColumnNull

isClosed

close

setExtensions

getExtensions

setAffectedByUris

getAffectedByUris

registerObserver

unregisterObserver