SQLiteCursor
public class SQLiteCursor
extends AbstractWindowedCursor
A Cursor implementation that exposes results from a query on a SQLiteDatabase
. SQLiteCursor is not internally synchronized so code using a SQLiteCursor from multiple threads should perform its own synchronization when using the SQLiteCursor.
Summary
Public methods |
void |
close() Closes the Cursor, releasing all of its resources and making it completely invalid. |
void |
deactivate() Deactivates the Cursor, making all calls on it fail until requery() is called. |
int |
getColumnIndex(String columnName) Returns the zero-based index for the given column name, or -1 if the column doesn't exist. |
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. |
SQLiteDatabase |
getDatabase() Get the database that this cursor is associated with. |
boolean |
onMove(int oldPosition, int newPosition) This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have. |
boolean |
requery() Performs the query that created the cursor again, refreshing its contents. |
void |
setSelectionArguments(String[] selectionArgs) Changes the selection arguments. |
void |
setWindow(CursorWindow window) Sets a new cursor window for the cursor to use. |
Protected methods |
void |
finalize() Release the native resources, if they haven't been released yet. |
Inherited methods |
From class android.database.AbstractWindowedCursor
void |
checkPosition() This function throws CursorIndexOutOfBoundsException if the cursor position is out of bounds. |
void |
copyStringToBuffer(int columnIndex, CharArrayBuffer buffer) Retrieves the requested column text and stores it in the buffer provided. |
byte[] |
getBlob(int columnIndex) Returns the value of the requested column as a byte array. |
double |
getDouble(int columnIndex) Returns the value of the requested column as a double. |
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. |
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. |
int |
getType(int columnIndex) Returns data type of the given column's value. |
CursorWindow |
getWindow() If the cursor is backed by a CursorWindow , returns a pre-filled window with the contents of the cursor, otherwise null. |
boolean |
hasWindow() Returns true if the cursor has an associated cursor window. |
boolean |
isBlob(int columnIndex) This method was deprecated in API level 11. Use getType(int) |
boolean |
isFloat(int columnIndex) This method was deprecated in API level 11. Use getType(int) |
boolean |
isLong(int columnIndex) This method was deprecated in API level 11. Use getType(int) |
boolean |
isNull(int columnIndex) Returns true if the value in the indicated column is null. |
boolean |
isString(int columnIndex) This method was deprecated in API level 11. Use getType(int) |
void |
setWindow(CursorWindow window) Sets a new cursor window for the cursor to use. |
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From class android.database.AbstractCursor
void |
checkPosition() This function throws CursorIndexOutOfBoundsException if the cursor position is out of bounds. |
void |
close() Closes the Cursor, releasing all of its resources and making it completely invalid. |
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. |
void |
fillWindow(int position, CursorWindow window) Copies cursor data into the window. |
void |
finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
byte[] |
getBlob(int column) 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. |
abstract 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. |
abstract int |
getCount() Returns the numbers of rows in the cursor. |
abstract double |
getDouble(int column) Returns the value of the requested column as a double. |
Bundle |
getExtras() Returns a bundle of extra values. |
abstract float |
getFloat(int column) Returns the value of the requested column as a float. |
abstract int |
getInt(int column) Returns the value of the requested column as an int. |
abstract long |
getLong(int column) Returns the value of the requested column as a long. |
Uri |
getNotificationUri() Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri(ContentResolver, Uri) . |
final int |
getPosition() Returns the current position of the cursor in the row set. |
abstract short |
getShort(int column) Returns the value of the requested column as a short. |
abstract String |
getString(int column) Returns the value of the requested column as a String. |
int |
getType(int column) Returns data type of the given column's value. |
Object |
getUpdatedField(int columnIndex) This method was deprecated in API level 11. Always returns null since Cursors do not support updating rows |
boolean |
getWantsAllOnMoveCalls() onMove() will only be called across processes if this method returns true. |
CursorWindow |
getWindow() If the cursor is backed by a CursorWindow , returns a pre-filled window with the contents of the cursor, otherwise null. |
final boolean |
isAfterLast() Returns whether the cursor is pointing to the position after the last row. |
final 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 |
isFieldUpdated(int columnIndex) This method was deprecated in API level 11. Always returns false since Cursors do not support updating rows |
final boolean |
isFirst() Returns whether the cursor is pointing to the first row. |
final boolean |
isLast() Returns whether the cursor is pointing to the last row. |
abstract boolean |
isNull(int column) Returns true if the value in the indicated column is null. |
final boolean |
move(int offset) Move the cursor by a relative amount, forward or backward, from the current position. |
final boolean |
moveToFirst() Move the cursor to the first row. |
final boolean |
moveToLast() Move the cursor to the last row. |
final boolean |
moveToNext() Move the cursor to the next row. |
final boolean |
moveToPosition(int position) Move the cursor to an absolute position. |
final boolean |
moveToPrevious() Move the cursor to the previous row. |
void |
onChange(boolean selfChange) Subclasses must call this method when they finish committing updates to notify all observers. |
boolean |
onMove(int oldPosition, int newPosition) This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have. |
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 |
setExtras(Bundle extras) Sets a Bundle that will be returned by getExtras() . |
void |
setNotificationUri(ContentResolver cr, Uri notifyUri) Specifies a content URI to watch for changes. |
void |
unregisterContentObserver(ContentObserver observer) Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver) . |
void |
unregisterDataSetObserver(DataSetObserver observer) Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver) . |
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From class java.lang.Object
Object |
clone() Creates and returns a copy of this object. |
boolean |
equals(Object obj) Indicates whether some other object is "equal to" this one. |
void |
finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
final Class<?> |
getClass() Returns the runtime class of this Object . |
int |
hashCode() Returns a hash code value for the object. |
final void |
notify() Wakes up a single thread that is waiting on this object's monitor. |
final void |
notifyAll() Wakes up all threads that are waiting on this object's monitor. |
String |
toString() Returns a string representation of the object. |
final void |
wait(long millis, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. |
final void |
wait(long millis) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed. |
final void |
wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. |
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From interface android.database.CrossProcessCursor
abstract void |
fillWindow(int position, CursorWindow window) Copies cursor data into the window. |
abstract CursorWindow |
getWindow() Returns a pre-filled window that contains the data within this cursor. |
abstract boolean |
onMove(int oldPosition, int newPosition) This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have. |
|
From interface android.database.Cursor
abstract void |
close() Closes the Cursor, releasing all of its resources and making it completely invalid. |
abstract void |
copyStringToBuffer(int columnIndex, CharArrayBuffer buffer) Retrieves the requested column text and stores it in the buffer provided. |
abstract void |
deactivate() This method was deprecated in API level 16. Since requery() is deprecated, so too is this. |
abstract byte[] |
getBlob(int columnIndex) Returns the value of the requested column as a byte array. |
abstract int |
getColumnCount() Return total number of columns |
abstract int |
getColumnIndex(String columnName) Returns the zero-based index for the given column name, or -1 if the column doesn't exist. |
abstract int |
getColumnIndexOrThrow(String columnName) Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist. |
abstract String |
getColumnName(int columnIndex) Returns the column name at the given zero-based column index. |
abstract 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. |
abstract int |
getCount() Returns the numbers of rows in the cursor. |
abstract double |
getDouble(int columnIndex) Returns the value of the requested column as a double. |
abstract Bundle |
getExtras() Returns a bundle of extra values. |
abstract float |
getFloat(int columnIndex) Returns the value of the requested column as a float. |
abstract int |
getInt(int columnIndex) Returns the value of the requested column as an int. |
abstract long |
getLong(int columnIndex) Returns the value of the requested column as a long. |
abstract Uri |
getNotificationUri() Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri(ContentResolver, Uri) . |
abstract int |
getPosition() Returns the current position of the cursor in the row set. |
abstract short |
getShort(int columnIndex) Returns the value of the requested column as a short. |
abstract String |
getString(int columnIndex) Returns the value of the requested column as a String. |
abstract int |
getType(int columnIndex) Returns data type of the given column's value. |
abstract boolean |
getWantsAllOnMoveCalls() onMove() will only be called across processes if this method returns true. |
abstract boolean |
isAfterLast() Returns whether the cursor is pointing to the position after the last row. |
abstract boolean |
isBeforeFirst() Returns whether the cursor is pointing to the position before the first row. |
abstract boolean |
isClosed() return true if the cursor is closed |
abstract boolean |
isFirst() Returns whether the cursor is pointing to the first row. |
abstract boolean |
isLast() Returns whether the cursor is pointing to the last row. |
abstract boolean |
isNull(int columnIndex) Returns true if the value in the indicated column is null. |
abstract boolean |
move(int offset) Move the cursor by a relative amount, forward or backward, from the current position. |
abstract boolean |
moveToFirst() Move the cursor to the first row. |
abstract boolean |
moveToLast() Move the cursor to the last row. |
abstract boolean |
moveToNext() Move the cursor to the next row. |
abstract boolean |
moveToPosition(int position) Move the cursor to an absolute position. |
abstract boolean |
moveToPrevious() Move the cursor to the previous row. |
abstract void |
registerContentObserver(ContentObserver observer) Register an observer that is called when changes happen to the content backing this cursor. |
abstract 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() . |
abstract boolean |
requery() This method was deprecated in API level 11. 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. |
abstract Bundle |
respond(Bundle extras) This is an out-of-band way for the the user of a cursor to communicate with the cursor. |
abstract void |
setExtras(Bundle extras) Sets a Bundle that will be returned by getExtras() . |
abstract void |
setNotificationUri(ContentResolver cr, Uri uri) Register to watch a content URI for changes. |
abstract void |
unregisterContentObserver(ContentObserver observer) Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver) . |
abstract void |
unregisterDataSetObserver(DataSetObserver observer) Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver) . |
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From interface java.io.Closeable
abstract void |
close() Closes this stream and releases any system resources associated with it. |
|
From interface java.lang.AutoCloseable
abstract void |
close() Closes this resource, relinquishing any underlying resources. |
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Public constructors
SQLiteCursor
SQLiteCursor (SQLiteDatabase db,
SQLiteCursorDriver driver,
String editTable,
SQLiteQuery query)
This constructor was deprecated in API level 11.
use SQLiteCursor(SQLiteCursorDriver, String, SQLiteQuery)
instead
Execute a query and provide access to its result set through a Cursor interface. For a query such as: SELECT name, birth, phone FROM myTable WHERE ... LIMIT 1,20 ORDER BY...
the column names (name, birth, phone) would be in the projection argument and everything from FROM
onward would be in the params argument.
Parameters |
db |
SQLiteDatabase : a reference to a Database object that is already constructed and opened. This param is not used any longer |
driver |
SQLiteCursorDriver
|
editTable |
String : the name of the table used for this query |
query |
SQLiteQuery : the rest of the query terms cursor is finalized |
SQLiteCursor
SQLiteCursor (SQLiteCursorDriver driver,
String editTable,
SQLiteQuery query)
Execute a query and provide access to its result set through a Cursor interface. For a query such as: SELECT name, birth, phone FROM myTable WHERE ... LIMIT 1,20 ORDER BY...
the column names (name, birth, phone) would be in the projection argument and everything from FROM
onward would be in the params argument.
Parameters |
driver |
SQLiteCursorDriver
|
editTable |
String : the name of the table used for this query |
query |
SQLiteQuery : the SQLiteQuery object associated with this cursor object. |
Public methods
close
void close ()
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.
deactivate
void deactivate ()
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.
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 |
String : the name of the target column. |
Returns |
int |
the zero-based column index for the given column name, or -1 if the column name does not exist. |
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 |
String[] |
the names of the columns returned in this query. |
getCount
int getCount ()
Returns the numbers of rows in the cursor.
Returns |
int |
the number of rows in the cursor. |
getDatabase
SQLiteDatabase getDatabase ()
Get the database that this cursor is associated with.
Returns |
SQLiteDatabase |
the SQLiteDatabase that this cursor is associated with. |
onMove
boolean onMove (int oldPosition,
int newPosition)
This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have. If it returns false the move function will also do so and the cursor will scroll to the beforeFirst position.
Parameters |
oldPosition |
int : the position that we're moving from |
newPosition |
int : the position that we're moving to |
Returns |
boolean |
true if the move is successful, false otherwise |
requery
boolean requery ()
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.
Returns |
boolean |
true if the requery succeeded, false if not, in which case the cursor becomes invalid. |
setSelectionArguments
void setSelectionArguments (String[] selectionArgs)
Changes the selection arguments. The new values take effect after a call to requery().
Parameters |
selectionArgs |
String
|
setWindow
void setWindow (CursorWindow window)
Sets a new cursor window for the cursor to use.
The cursor takes ownership of the provided cursor window; the cursor window will be closed when the cursor is closed or when the cursor adopts a new cursor window.
If the cursor previously had a cursor window, then it is closed when the new cursor window is assigned.
Parameters |
window |
CursorWindow : The new cursor window, typically a remote cursor window. |
Protected methods
finalize
void finalize ()
Release the native resources, if they haven't been released yet.