| android.database.Cursor |
 Known Indirect Subclasses
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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.
| Constants | |||||||||||
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| int | FIELD_TYPE_BLOB | Value returned by getType(int) if the specified column type is blob |
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| int | FIELD_TYPE_FLOAT | Value returned by getType(int) if the specified column type is float |
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| int | FIELD_TYPE_INTEGER | Value returned by getType(int) if the specified column type is integer |
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| int | FIELD_TYPE_NULL | Value returned by getType(int) if the specified column is null |
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| int | FIELD_TYPE_STRING | Value returned by getType(int) if the specified column type is string |
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| Public Methods | |||||||||||
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Closes the Cursor, releasing all of its resources and making it completely invalid.
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Retrieves the requested column text and stores it in the buffer provided.
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This method was deprecated
in API level 16.
Since
requery() is deprecated, so too is this.
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Returns the value of the requested column as a byte array.
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Return total number of columns
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Returns the zero-based index for the given column name, or -1 if the column doesn't exist.
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Returns the zero-based index for the given column name, or throws
IllegalArgumentException if the column doesn't exist. | |||||||||||
Returns the column name at the given zero-based column index.
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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.
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Returns the numbers of rows in the cursor.
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Returns the value of the requested column as a double.
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Returns a bundle of extra values.
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Returns the value of the requested column as a float.
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Returns the value of the requested column as an int.
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Returns the value of the requested column as a long.
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Return the URI at which notifications of changes in this Cursor's data
will be delivered, as previously set by
setNotificationUri(ContentResolver, Uri). | |||||||||||
Returns the current position of the cursor in the row set.
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Returns the value of the requested column as a short.
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Returns the value of the requested column as a String.
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Returns data type of the given column's value.
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onMove() will only be called across processes if this method returns true.
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Returns whether the cursor is pointing to the position after the last
row.
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Returns whether the cursor is pointing to the position before the first
row.
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return true if the cursor is closed
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Returns whether the cursor is pointing to the first row.
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Returns whether the cursor is pointing to the last row.
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Returns
true if the value in the indicated column is null. | |||||||||||
Move the cursor by a relative amount, forward or backward, from the
current position.
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Move the cursor to the first row.
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Move the cursor to the last row.
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Move the cursor to the next row.
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Move the cursor to an absolute position.
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Move the cursor to the previous row.
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Register an observer that is called when changes happen to the content backing this cursor.
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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(). | |||||||||||
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.
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This is an out-of-band way for the the user of a cursor to communicate with the cursor.
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Register to watch a content URI for changes.
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Unregister an observer that has previously been registered with this
cursor via
registerContentObserver(ContentObserver). | |||||||||||
Unregister an observer that has previously been registered with this
cursor via
registerContentObserver(ContentObserver). | |||||||||||
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[Expand]
Inherited Methods | |||||||||||
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From interface
java.io.Closeable
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From interface
java.lang.AutoCloseable
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Value returned by getType(int) if the specified column type is blob
Value returned by getType(int) if the specified column type is float
Value returned by getType(int) if the specified column type is integer
Value returned by getType(int) if the specified column is null
Value returned by getType(int) if the specified column type is string
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.
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
| columnIndex | the zero-based index of the target column. if the target column is null, return buffer |
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| buffer | the buffer to copy the text into. |
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.
| columnIndex | the zero-based index of the target column. |
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Return total number of columns
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.
| columnName | the name of the target column. |
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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.
| columnName | the name of the target column. |
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| IllegalArgumentException | if the column does not exist |
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Returns the column name at the given zero-based column index.
| columnIndex | the zero-based index of the target column. |
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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 numbers of rows in the cursor.
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.
| columnIndex | the zero-based index of the target column. |
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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.
Bundle.EMPTY if there
are no values. Never null.
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.
| columnIndex | the zero-based index of the target column. |
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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.
| columnIndex | the zero-based index of the target column. |
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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.
| columnIndex | the zero-based index of the target column. |
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Return the URI at which notifications of changes in this Cursor's data
will be delivered, as previously set by setNotificationUri(ContentResolver, Uri).
ContentResolver.registerContentObserver to find out about changes to this Cursor's
data. May be null if no notification URI has been set.
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 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.
| columnIndex | the zero-based index of the target column. |
|---|
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.
| columnIndex | the zero-based index of the target column. |
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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.
Returned column types are
| columnIndex | the zero-based index of the target column. |
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onMove() will only be called across processes if this method returns true.
Returns whether the cursor is pointing to the position after the last row.
Returns whether the cursor is pointing to the position before the first row.
return true if the cursor is closed
Returns whether the cursor is pointing to the first row.
Returns whether the cursor is pointing to the last row.
Returns true if the value in the indicated column is null.
| columnIndex | the zero-based index of the target column. |
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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.
| offset | the offset to be applied from the current position. |
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Move the cursor to the first row.
This method will return false if the cursor is empty.
Move the cursor to the last row.
This method will return false if the cursor is empty.
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.
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.
| position | the zero-based position to move to. |
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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.
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.
| observer | the object that gets notified when the content backing the cursor changes. |
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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().
| observer | the object that gets notified when the cursors data set changes. |
|---|
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.
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.
This is an out-of-band way for the 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.
| extras | extra values, or Bundle.EMPTY.
Never null. |
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Bundle.EMPTY.
Never null.
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.
| cr | The content resolver from the caller's context. The listener attached to this resolver will be notified. |
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| uri | The content URI to watch. |
Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver).
| observer | the object to unregister. |
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Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver).
| observer | the object to unregister. |
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