Interface CursorExt

All Superinterfaces:

Cursor

public interface CursorExt
extends Cursor

Optional cursor capabilities, in the same spirit as RowExt.

These are not on Cursor itself because that interface is public and is implemented outside this repository; adding a method to it would break every third party library that provides one. Reach these through the static helpers on Database, which degrade gracefully on a cursor that does not implement this interface:

Database.beforeFirst(cursor);
int rows = Database.count(cursor); // -1 when the port cannot say cheaply

Every cursor returned by a Codename One port implements this.

Method Summary

Modifier and Type	Method	Description
void	beforeFirst()	Rewinds to before the first row, without landing on a row.
int	getCount()	Returns the number of rows in the result set, or -1 when the port cannot determine it without walking the whole set.

Methods inherited from interface Cursor

close, first, getColumnCount, getColumnIndex, getColumnName, getPosition, getRow, last, next, position, prev

Method Details

beforeFirst

void beforeFirst()
          throws IOException

Rewinds to before the first row, without landing on a row.

After this call Cursor#getPosition() reports -1 and Cursor#getRow() throws, exactly as on a freshly returned cursor. This is the operation Cursor#position(int) performs when given -1.

Throws

• IOException: if the cursor is closed or the rewind fails

Throws:

IOException

getCount

int getCount()
      throws IOException

Returns the number of rows in the result set, or -1 when the port cannot determine it without walking the whole set.

Ports that already track the count report it directly. Ports backed by a forward-only statement have to step to the end and rewind, so they report the count once it is known and -1 before that. Treat -1 as "unknown", not as "empty".

Returns

the row count, or -1 when it is not cheaply available

Throws

• IOException: if the cursor is closed

Throws:

IOException