Transaction

With the following procedure, it is possible to move data from a primary table to a secondary table for archival purposes. This specific example moves data on the basis of a date column in the primary table. The number of days (related to  the current date/time) to remain in the primary table is passed to the procedure. Start procedure with ‘CALL pCleanUPTable (35)’.

DELIMITER //

CREATE PROCEDURE pCleanUpTable(IN iDays INT)

  BEGIN
    START TRANSACTION;
    SELECT (now() - interval iDays day) INTO @dtDeleteFrom;
    SAVEPOINT PreCleanUP;
    -- Copy old records to new archive/secundary  table...
    INSERT INTO sectab (primtab_id, value1, value2, value3, datum)
    SELECT id, value1, value2, value3, datum from primtab where datum < @dtDeleteFrom;
    SELECT ROW_COUNT() INTO @iRowsCopy;

    -- Remove records from primary table...
    DELETE FROM primtab WHERE datum < @dtDeleteFrom;
    SELECT ROW_COUNT() INTO @iRowsDelete;

    -- Check if rows copied -eq rows deleted...
    IF (@iRowsCopy = @iRowsDelete) THEN
      COMMIT;
      SELECT 'Success - Committed!' AS Result, @iRowsCopy AS RowsCopy, @iRowsDelete AS RowsDelete;
    ELSE
      ROLLBACK TO PreCleanUp;
      SELECT 'Failure - ROLLBACK!' AS Result, @iRowsCopy AS RowsCopy, @iRowsDelete AS RowsDelete;
    END IF;
  END //

DELIMITER ;

In bovenstaande voorbeeld is gebruik gemaakt van de volgende InnoDB tabellen.

[primtab]
+--------+------------------+------+-----+---------+----------------+
| Field  | Type             | Null | Key | Default | Extra          |
+--------+------------------+------+-----+---------+----------------+
| id     | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| value1 | varchar(75)      | YES  |     | NULL    |                |
| value2 | varchar(75)      | YES  |     | NULL    |                |
| value3 | varchar(75)      | YES  |     | NULL    |                |
| datum  | datetime         | YES  |     | NULL    |                |
+--------+------------------+------+-----+---------+----------------+

[sectab]
+------------+------------------+------+-----+---------+----------------+
| Field      | Type             | Null | Key | Default | Extra          |
+------------+------------------+------+-----+---------+----------------+
| id         | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| primtab_id | int(10)          | YES  |     | NULL    |                |
| value1     | varchar(75)      | YES  |     | NULL    |                |
| value2     | varchar(75)      | YES  |     | NULL    |                |
| value3     | varchar(75)      | YES  |     | NULL    |                |
| datum      | datetime         | YES  |     | NULL    |                |
+------------+------------------+------+-----+---------+----------------+