Precautions for using DB2 cursors

1. Procedure for using a cursor

(1) define a cursor

Exec SQL DECLARE MY_CURSOR CURSOR ........

(2) Open the cursor

Exec SQL OPEN MY_CURSOR;

(3) read cursor

Exec SQL FETCH MY_CURSOR INTO: MY_Stru;

(4) Close the cursor

Exec SQL CLOSE MY_CURSOR;

2. Notes

(1) The SQLCODE judgment should be added to each step.

(2) If a COMMIT or roll back operation exists after the cursor is read, The with hold option must be added when the cursor is defined to ensure that the cursor is not closed after submission.

(3) After the cursor is read, a logical operation is generally performed. If an error is returned and the operation exits, the cursor must be closed.

(4) for read-ONLY operations, add for read only when defining the cursor

(5) for update operations, add for update when defining the cursor. You can also specify the updated field.