Cursor

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android.database
Interface Cursor

All Known Subinterfaces:: CrossProcessCursor

All Known Implementing Classes:: AbstractCursor, AbstractWindowedCursor, BulkCursorToCursorAdaptor, CursorWrapper, MatrixCursor, MergeCursor, SQLiteCursor

public interface Cursor

This interface provides random read-write access to the result set returned by a database query.

Method Summary
`void`	`abortUpdates()` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`void`	`close()` Closes the Cursor, releasing all of its resources and making it completely invalid.
`boolean`	`commitUpdates()` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`commitUpdates(Map<? extends Long,? extends Map<String,Object>> values)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`void`	`copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)` Retrieves the requested column text and stores it in the buffer provided.
`void`	`deactivate()` Deactivates the Cursor, making all calls on it fail until `requery()` is called.
`boolean`	`deleteRow()` Deprecated. use `ContentResolver.delete(Uri, String, String[])`
`byte[]`	`getBlob(int columnIndex)` Returns the value of the requested column as a byte array.
`int`	`getColumnCount()` Return total number of columns
`int`	`getColumnIndex(String columnName)` Returns the zero-based index for the given column name, or -1 if the column doesn't exist.
`int`	`getColumnIndexOrThrow(String columnName)` Returns the zero-based index for the given column name, or throws `IllegalArgumentException` if the column doesn't exist.
`String`	`getColumnName(int columnIndex)` Returns the column name at the given zero-based column index.
`String[]`	`getColumnNames()` Returns a string array holding the names of all of the columns in the result set in the order in which they were listed in the result.
`int`	`getCount()` Returns the numbers of rows in the cursor.
`double`	`getDouble(int columnIndex)` Returns the value of the requested column as a double.
`Bundle`	`getExtras()` Returns a bundle of extra values.
`float`	`getFloat(int columnIndex)` Returns the value of the requested column as a float.
`int`	`getInt(int columnIndex)` Returns the value of the requested column as an int.
`long`	`getLong(int columnIndex)` Returns the value of the requested column as a long.
`int`	`getPosition()` Returns the current position of the cursor in the row set.
`short`	`getShort(int columnIndex)` Returns the value of the requested column as a short.
`String`	`getString(int columnIndex)` Returns the value of the requested column as a String.
`boolean`	`getWantsAllOnMoveCalls()` onMove() will only be called across processes if this method returns true.
`boolean`	`hasUpdates()` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`isAfterLast()` Returns whether the cursor is pointing to the position after the last row.
`boolean`	`isBeforeFirst()` Returns whether the cursor is pointing to the position before the first row.
`boolean`	`isClosed()` return true if the cursor is closed
`boolean`	`isFirst()` Returns whether the cursor is pointing to the first row.
`boolean`	`isLast()` Returns whether the cursor is pointing to the last row.
`boolean`	`isNull(int columnIndex)` Returns `true` if the value in the indicated column is null.
`boolean`	`move(int offset)` Move the cursor by a relative amount, forward or backward, from the current position.
`boolean`	`moveToFirst()` Move the cursor to the first row.
`boolean`	`moveToLast()` Move the cursor to the last row.
`boolean`	`moveToNext()` Move the cursor to the next row.
`boolean`	`moveToPosition(int position)` Move the cursor to an absolute position.
`boolean`	`moveToPrevious()` Move the cursor to the previous row.
`void`	`registerContentObserver(ContentObserver observer)` Register an observer that is called when changes happen to the content backing this cursor.
`void`	`registerDataSetObserver(DataSetObserver observer)` Register an observer that is called when changes happen to the contents of the this cursors data set, for example, when the data set is changed via `requery()`, `deactivate()`, or `close()`.
`boolean`	`requery()` Performs the query that created the cursor again, refreshing its contents.
`Bundle`	`respond(Bundle extras)` This is an out-of-band way for the the user of a cursor to communicate with the cursor.
`void`	`setNotificationUri(ContentResolver cr, Uri uri)` Register to watch a content URI for changes.
`boolean`	`supportsUpdates()` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`void`	`unregisterContentObserver(ContentObserver observer)` Unregister an observer that has previously been registered with this cursor via `registerContentObserver(android.database.ContentObserver)`.
`void`	`unregisterDataSetObserver(DataSetObserver observer)` Unregister an observer that has previously been registered with this cursor via `registerContentObserver(android.database.ContentObserver)`.
`boolean`	`updateBlob(int columnIndex, byte[] value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateDouble(int columnIndex, double value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateFloat(int columnIndex, float value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateInt(int columnIndex, int value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateLong(int columnIndex, long value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateShort(int columnIndex, short value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateString(int columnIndex, String value)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods
`boolean`	`updateToNull(int columnIndex)` Deprecated. use the `ContentResolver` update methods instead of the Cursor update methods

Method Detail

getCount

int getCount()

Returns the numbers of rows in the cursor.

Returns:: the number of rows in the cursor.

getPosition

int getPosition()

Returns the current position of the cursor in the row set. The value is zero-based. When the row set is first returned the cursor will be at positon -1, which is before the first row. After the last row is returned another call to next() will leave the cursor past the last entry, at a position of count().

Returns:: the current cursor position.

move

boolean move(int offset)

Move the cursor by a relative amount, forward or backward, from the current position. Positive offsets move forwards, negative offsets move backwards. If the final position is outside of the bounds of the result set then the resultant position will be pinned to -1 or count() depending on whether the value is off the front or end of the set, respectively.

This method will return true if the requested destination was reachable, otherwise, it returns false. For example, if the cursor is at currently on the second entry in the result set and move(-5) is called, the position will be pinned at -1, and false will be returned.

Parameters:: offset - the offset to be applied from the current position.
Returns:: whether the requested move fully succeeded.

moveToPosition

boolean moveToPosition(int position)

Move the cursor to an absolute position. The valid range of values is -1 <= position <= count.

This method will return true if the request destination was reachable, otherwise, it returns false.

Parameters:: position - the zero-based position to move to.
Returns:: whether the requested move fully succeeded.

moveToFirst

boolean moveToFirst()

Move the cursor to the first row.

This method will return false if the cursor is empty.

Returns:: whether the move succeeded.

moveToLast

boolean moveToLast()

Move the cursor to the last row.

This method will return false if the cursor is empty.

Returns:: whether the move succeeded.

moveToNext

boolean moveToNext()

Move the cursor to the next row.

This method will return false if the cursor is already past the last entry in the result set.

Returns:: whether the move succeeded.

moveToPrevious

boolean moveToPrevious()

Move the cursor to the previous row.

This method will return false if the cursor is already before the first entry in the result set.

Returns:: whether the move succeeded.

isFirst

boolean isFirst()

Returns whether the cursor is pointing to the first row.

Returns:: whether the cursor is pointing at the first entry.

isLast

boolean isLast()

Returns whether the cursor is pointing to the last row.

Returns:: whether the cursor is pointing at the last entry.

isBeforeFirst

boolean isBeforeFirst()

Returns whether the cursor is pointing to the position before the first row.

Returns:: whether the cursor is before the first result.

isAfterLast

boolean isAfterLast()

Returns whether the cursor is pointing to the position after the last row.

Returns:: whether the cursor is after the last result.

deleteRow

@Deprecated
boolean deleteRow()

Deprecated. use ContentResolver.delete(Uri, String, String[])

Removes the row at the current cursor position from the underlying data store. After this method returns the cursor will be pointing to the row after the row that is deleted. This has the side effect of decrementing the result of count() by one.

The query must have the row ID column in its selection, otherwise this call will fail.

Returns:: whether the record was successfully deleted.

getColumnIndex

int getColumnIndex(String columnName)

Returns the zero-based index for the given column name, or -1 if the column doesn't exist. If you expect the column to exist use getColumnIndexOrThrow(String) instead, which will make the error more clear.

Parameters:: columnName - the name of the target column.
Returns:: the zero-based column index for the given column name, or -1 if the column name does not exist.
See Also:: getColumnIndexOrThrow(String)

getColumnIndexOrThrow

int getColumnIndexOrThrow(String columnName)
                          throws IllegalArgumentException

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist. If you're not sure if a column will exist or not use getColumnIndex(String) and check for -1, which is more efficient than catching the exceptions.

Parameters:: columnName - the name of the target column.
Returns:: the zero-based column index for the given column name
Throws:: IllegalArgumentException - if the column does not exist
See Also:: getColumnIndex(String)

getColumnName

String getColumnName(int columnIndex)

Returns the column name at the given zero-based column index.

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the column name for the given column index.

getColumnNames

String[] getColumnNames()

Returns a string array holding the names of all of the columns in the result set in the order in which they were listed in the result.

Returns:: the names of the columns returned in this query.

getColumnCount

int getColumnCount()

Return total number of columns

Returns:: number of columns

getBlob

byte[] getBlob(int columnIndex)

Returns the value of the requested column as a byte array.

If the native content of that column is not blob exception may throw

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a byte array.

getString

String getString(int columnIndex)

Returns the value of the requested column as a String.

If the native content of that column is not text the result will be the result of passing the column value to String.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a String.

copyStringToBuffer

void copyStringToBuffer(int columnIndex,
                        CharArrayBuffer buffer)

Retrieves the requested column text and stores it in the buffer provided. If the buffer size is not sufficient, a new char buffer will be allocated and assigned to CharArrayBuffer.data

Parameters:: columnIndex - the zero-based index of the target column. if the target column is null, return buffer; buffer - the buffer to copy the text into.

getShort

short getShort(int columnIndex)

Returns the value of the requested column as a short.

If the native content of that column is not numeric the result will be the result of passing the column value to Short.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a short.

getInt

int getInt(int columnIndex)

Returns the value of the requested column as an int.

If the native content of that column is not numeric the result will be the result of passing the column value to Integer.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as an int.

getLong

long getLong(int columnIndex)

Returns the value of the requested column as a long.

If the native content of that column is not numeric the result will be the result of passing the column value to Long.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a long.

getFloat

float getFloat(int columnIndex)

Returns the value of the requested column as a float.

If the native content of that column is not numeric the result will be the result of passing the column value to Float.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a float.

getDouble

double getDouble(int columnIndex)

Returns the value of the requested column as a double.

If the native content of that column is not numeric the result will be the result of passing the column value to Double.valueOf(x).

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: the value of that column as a double.

isNull

boolean isNull(int columnIndex)

Returns true if the value in the indicated column is null.

Parameters:: columnIndex - the zero-based index of the target column.
Returns:: whether the column value is null.