Added in API level 1

Cursor


interface Cursor : Closeable
android.database.Cursor

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

Cursor implementations are not required to be synchronized so code using a Cursor from multiple threads should perform its own synchronization when using the Cursor.

Implementations should subclass AbstractCursor.

Summary

Constants
static Int

Value returned by getType(int) if the specified column type is blob

static Int

Value returned by getType(int) if the specified column type is float

static Int

Value returned by getType(int) if the specified column type is integer

static Int

Value returned by getType(int) if the specified column is null

static Int

Value returned by getType(int) if the specified column type is string

Public methods
abstract Unit

Closes the Cursor, releasing all of its resources and making it completely invalid.

abstract Unit
copyStringToBuffer(columnIndex: Int, buffer: CharArrayBuffer!)

Retrieves the requested column text and stores it in the buffer provided.

abstract Unit

Deactivates the Cursor, making all calls on it fail until requery is called.

abstract ByteArray!
getBlob(columnIndex: Int)

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

abstract Int

Return total number of columns

abstract Int
getColumnIndex(columnName: String!)

Returns the zero-based index for the given column name, or -1 if the column doesn't exist.

abstract Int

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist.

abstract String!
getColumnName(columnIndex: Int)

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

abstract Array<String!>!

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.

abstract Int

Returns the numbers of rows in the cursor.

abstract Double
getDouble(columnIndex: Int)

Returns the value of the requested column as a double.

abstract Bundle!

Returns a bundle of extra values.

abstract Float
getFloat(columnIndex: Int)

Returns the value of the requested column as a float.

abstract Int
getInt(columnIndex: Int)

Returns the value of the requested column as an int.

abstract Long
getLong(columnIndex: Int)

Returns the value of the requested column as a long.

abstract Uri!

Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri.

open MutableList<Uri!>?

Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUris.

abstract Int

Returns the current position of the cursor in the row set.

abstract Short
getShort(columnIndex: Int)

Returns the value of the requested column as a short.

abstract String!
getString(columnIndex: Int)

Returns the value of the requested column as a String.

abstract Int
getType(columnIndex: Int)

Returns data type of the given column's value.

abstract Boolean

onMove() will only be called across processes if this method returns true.

abstract Boolean

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

abstract Boolean

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

abstract Boolean

return true if the cursor is closed

abstract Boolean

Returns whether the cursor is pointing to the first row.

abstract Boolean

Returns whether the cursor is pointing to the last row.

abstract Boolean
isNull(columnIndex: Int)

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

abstract Boolean
move(offset: Int)

Move the cursor by a relative amount, forward or backward, from the current position.

abstract Boolean

Move the cursor to the first row.

abstract Boolean

Move the cursor to the last row.

abstract Boolean

Move the cursor to the next row.

abstract Boolean
moveToPosition(position: Int)

Move the cursor to an absolute position.

abstract Boolean

Move the cursor to the previous row.

abstract Unit

Register an observer that is called when changes happen to the content backing this cursor.

abstract Unit

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().

abstract Boolean

Performs the query that created the cursor again, refreshing its contents.

abstract Bundle!
respond(extras: Bundle!)

This is an out-of-band way for the user of a cursor to communicate with the cursor.

abstract Unit
setExtras(extras: Bundle!)

Sets a Bundle that will be returned by getExtras().

abstract Unit

Register to watch a content URI for changes.

open Unit

Similar to setNotificationUri(android.content.ContentResolver,android.net.Uri), except this version allows to watch multiple content URIs for changes.

abstract Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

abstract Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Constants

FIELD_TYPE_BLOB

Added in API level 11
static val FIELD_TYPE_BLOB: Int

Value returned by getType(int) if the specified column type is blob

Value: 4

FIELD_TYPE_FLOAT

Added in API level 11
static val FIELD_TYPE_FLOAT: Int

Value returned by getType(int) if the specified column type is float

Value: 2

FIELD_TYPE_INTEGER

Added in API level 11
static val FIELD_TYPE_INTEGER: Int

Value returned by getType(int) if the specified column type is integer

Value: 1

FIELD_TYPE_NULL

Added in API level 11
static val FIELD_TYPE_NULL: Int

Value returned by getType(int) if the specified column is null

Value: 0

FIELD_TYPE_STRING

Added in API level 11
static val FIELD_TYPE_STRING: Int

Value returned by getType(int) if the specified column type is string

Value: 3

Public methods

close

Added in API level 1
abstract fun close(): Unit

Closes the Cursor, releasing all of its resources and making it completely invalid. Unlike deactivate() a call to requery() will not make the Cursor valid again.

Exceptions
java.lang.Exception if this resource cannot be closed
java.io.IOException if an I/O error occurs

copyStringToBuffer

Added in API level 1
abstract fun copyStringToBuffer(
    columnIndex: Int,
    buffer: CharArrayBuffer!
): Unit

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 Int: the zero-based index of the target column. if the target column is null, return buffer Value is 0 or greater
buffer CharArrayBuffer!: the buffer to copy the text into.

deactivate

Added in API level 1
Deprecated in API level 16
abstract fun deactivate(): Unit

Deprecated: Since requery() is deprecated, so too is this.

Deactivates the Cursor, making all calls on it fail until requery is called. Inactive Cursors use fewer resources than active Cursors. Calling requery will make the cursor active again.

getBlob

Added in API level 1
abstract fun getBlob(columnIndex: Int): ByteArray!

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

The result and whether this method throws an exception when the column value is null or the column type is not a blob type is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
ByteArray! the value of that column as a byte array.

getColumnCount

Added in API level 1
abstract fun getColumnCount(): Int

Return total number of columns

Return
Int number of columns Value is 0 or greater

getColumnIndex

Added in API level 1
abstract fun getColumnIndex(columnName: String!): Int

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(java.lang.String) instead, which will make the error more clear.

Parameters
columnName String!: the name of the target column.
Return
Int the zero-based column index for the given column name, or -1 if the column name does not exist. Value is -1 or greater

getColumnIndexOrThrow

Added in API level 1
abstract fun getColumnIndexOrThrow(columnName: String!): Int

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(java.lang.String) and check for -1, which is more efficient than catching the exceptions.

Parameters
columnName String!: the name of the target column.
Return
Int the zero-based column index for the given column name Value is 0 or greater
Exceptions
java.lang.IllegalArgumentException if the column does not exist

getColumnName

Added in API level 1
abstract fun getColumnName(columnIndex: Int): String!

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

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
String! the column name for the given column index.

getColumnNames

Added in API level 1
abstract fun getColumnNames(): Array<String!>!

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.

Return
Array<String!>! the names of the columns returned in this query.

getCount

Added in API level 1
abstract fun getCount(): Int

Returns the numbers of rows in the cursor.

Return
Int the number of rows in the cursor. Value is 0 or greater

getDouble

Added in API level 1
abstract fun getDouble(columnIndex: Int): Double

Returns the value of the requested column as a double.

The result and whether this method throws an exception when the column value is null, the column type is not a floating-point type, or the floating-point value is not representable as a double value is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Double the value of that column as a double.

getExtras

Added in API level 1
abstract fun getExtras(): Bundle!

Returns a bundle of extra values. This is an optional way for cursors to provide out-of-band metadata to their users. One use of this is for reporting on the progress of network requests that are required to fetch data for the cursor.

These values may only change when requery is called.

Return
Bundle! cursor-defined values, or Bundle.EMPTY if there are no values. Never null.

getFloat

Added in API level 1
abstract fun getFloat(columnIndex: Int): Float

Returns the value of the requested column as a float.

The result and whether this method throws an exception when the column value is null, the column type is not a floating-point type, or the floating-point value is not representable as a float value is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Float the value of that column as a float.

getInt

Added in API level 1
abstract fun getInt(columnIndex: Int): Int

Returns the value of the requested column as an int.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Integer.MIN_VALUE, Integer.MAX_VALUE] is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Int the value of that column as an int.

getLong

Added in API level 1
abstract fun getLong(columnIndex: Int): Long

Returns the value of the requested column as a long.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Long.MIN_VALUE, Long.MAX_VALUE] is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Long the value of that column as a long.

getNotificationUri

Added in API level 19
abstract fun getNotificationUri(): Uri!

Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri.

Return
Uri! Returns a URI that can be used with ContentResolver.registerContentObserver to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getNotificationUris

Added in API level 29
open fun getNotificationUris(): MutableList<Uri!>?

Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUris.

If this is not implemented, this is equivalent to calling getNotificationUri().

Return
MutableList<Uri!>? Returns URIs that can be used with ContentResolver.registerContentObserver to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getPosition

Added in API level 1
abstract fun getPosition(): Int

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().

Return
Int the current cursor position. Value is -1 or greater

getShort

Added in API level 1
abstract fun getShort(columnIndex: Int): Short

Returns the value of the requested column as a short.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Short.MIN_VALUE, Short.MAX_VALUE] is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Short the value of that column as a short.

getString

Added in API level 1
abstract fun getString(columnIndex: Int): String!

Returns the value of the requested column as a String.

The result and whether this method throws an exception when the column value is null or the column type is not a string type is implementation-defined.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
String! the value of that column as a String.

getType

Added in API level 11
abstract fun getType(columnIndex: Int): Int

Returns data type of the given column's value. The preferred type of the column is returned but the data may be converted to other types as documented in the get-type methods such as getInt(int), getFloat(int) etc.

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Int column value type Value is android.database.Cursor#FIELD_TYPE_NULL, android.database.Cursor#FIELD_TYPE_INTEGER, android.database.Cursor#FIELD_TYPE_FLOAT, android.database.Cursor#FIELD_TYPE_STRING, or android.database.Cursor#FIELD_TYPE_BLOB

getWantsAllOnMoveCalls

Added in API level 1
abstract fun getWantsAllOnMoveCalls(): Boolean

onMove() will only be called across processes if this method returns true.

Return
Boolean whether all cursor movement should result in a call to onMove().

isAfterLast

Added in API level 1
abstract fun isAfterLast(): Boolean

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

Return
Boolean whether the cursor is after the last result.

isBeforeFirst

Added in API level 1
abstract fun isBeforeFirst(): Boolean

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

Return
Boolean whether the cursor is before the first result.

isClosed

Added in API level 1
abstract fun isClosed(): Boolean

return true if the cursor is closed

Return
Boolean true if the cursor is closed.

isFirst

Added in API level 1
abstract fun isFirst(): Boolean

Returns whether the cursor is pointing to the first row.

Return
Boolean whether the cursor is pointing at the first entry.

isLast

Added in API level 1
abstract fun isLast(): Boolean

Returns whether the cursor is pointing to the last row.

Return
Boolean whether the cursor is pointing at the last entry.

isNull

Added in API level 1
abstract fun isNull(columnIndex: Int): Boolean

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

Parameters
columnIndex Int: the zero-based index of the target column. Value is 0 or greater
Return
Boolean whether the column value is null.

move

Added in API level 1
abstract fun move(offset: Int): Boolean

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 Int: the offset to be applied from the current position.
Return
Boolean whether the requested move fully succeeded.

moveToFirst

Added in API level 1
abstract fun moveToFirst(): Boolean

Move the cursor to the first row.

This method will return false if the cursor is empty.

Return
Boolean whether the move succeeded.

moveToLast

Added in API level 1
abstract fun moveToLast(): Boolean

Move the cursor to the last row.

This method will return false if the cursor is empty.

Return
Boolean whether the move succeeded.

moveToNext

Added in API level 1
abstract fun moveToNext(): Boolean

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.

Return
Boolean whether the move succeeded.

moveToPosition

Added in API level 1
abstract fun moveToPosition(position: Int): Boolean

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 Int: the zero-based position to move to. Value is -1 or greater
Return
Boolean whether the requested move fully succeeded.

moveToPrevious

Added in API level 1
abstract fun moveToPrevious(): Boolean

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.

Return
Boolean whether the move succeeded.

registerContentObserver

Added in API level 1
abstract fun registerContentObserver(observer: ContentObserver!): Unit

Register an observer that is called when changes happen to the content backing this cursor. Typically the data set won't change until requery() is called.

Parameters
observer ContentObserver!: the object that gets notified when the content backing the cursor changes.

registerDataSetObserver

Added in API level 1
abstract fun registerDataSetObserver(observer: DataSetObserver!): Unit

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().

Parameters
observer DataSetObserver!: the object that gets notified when the cursors data set changes.

requery

Added in API level 1
Deprecated in API level 15
abstract fun requery(): Boolean

Deprecated: Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back.

Performs the query that created the cursor again, refreshing its contents. This may be done at any time, including after a call to deactivate. Since this method could execute a query on the database and potentially take a while, it could cause ANR if it is called on Main (UI) thread. A warning is printed if this method is being executed on Main thread.

Return
Boolean true if the requery succeeded, false if not, in which case the cursor becomes invalid.

respond

Added in API level 1
abstract fun respond(extras: Bundle!): Bundle!

This is an out-of-band way for the user of a cursor to communicate with the cursor. The structure of each bundle is entirely defined by the cursor.

One use of this is to tell a cursor that it should retry its network request after it reported an error.

Parameters
extras Bundle!: extra values, or Bundle.EMPTY. Never null.
Return
Bundle! extra values, or Bundle.EMPTY. Never null.

setExtras

Added in API level 23
abstract fun setExtras(extras: Bundle!): Unit

Sets a Bundle that will be returned by getExtras().

Parameters
extras Bundle!: Bundle to set, or null to set an empty bundle.

setNotificationUri

Added in API level 1
abstract fun setNotificationUri(
    cr: ContentResolver!,
    uri: Uri!
): Unit

Register to watch a content URI for changes. This can be the URI of a specific data row (for example, "content://my_provider_type/23"), or a a generic URI for a content type.

Calling this overrides any previous call to setNotificationUris(android.content.ContentResolver,java.util.List).

Parameters
cr ContentResolver!: The content resolver from the caller's context. The listener attached to this resolver will be notified.
uri Uri!: The content URI to watch.

setNotificationUris

Added in API level 29
open fun setNotificationUris(
    cr: ContentResolver,
    uris: MutableList<Uri!>
): Unit

Similar to setNotificationUri(android.content.ContentResolver,android.net.Uri), except this version allows to watch multiple content URIs for changes.

If this is not implemented, this is equivalent to calling setNotificationUri(android.content.ContentResolver,android.net.Uri) with the first URI in uris.

Calling this overrides any previous call to setNotificationUri(android.content.ContentResolver,android.net.Uri).

Parameters
cr ContentResolver: The content resolver from the caller's context. The listener attached to this resolver will be notified. This value cannot be null.
uris MutableList<Uri!>: The content URIs to watch. This value cannot be null.

unregisterContentObserver

Added in API level 1
abstract fun unregisterContentObserver(observer: ContentObserver!): Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Parameters
observer ContentObserver!: the object to unregister.

unregisterDataSetObserver

Added in API level 1
abstract fun unregisterDataSetObserver(observer: DataSetObserver!): Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Parameters
observer DataSetObserver!: the object to unregister.