Question

Seen a lot for dropping tables using a wildcard but not a direct SQL statement except this one:

http://azimyasin.wordpress.com/2007/08/11/mysql-dropping-multiple-tables/

It says:

SHOW TABLES LIKE ‘phpbb_%’;

then DROP TABLES, is there a neat way to combine this all into one SQL Statement?

Answer 1

You could use dynamic SQL to do it, inside a stored procedure. It’d look something like this (untested):

CREATE PROCEDURE drop_like (IN pattern VARCHAR(64))
BEGIN
  DECLARE q tinytext;
  DECLARE done INT DEFAULT FALSE;
  DECLARE cur CURSOR FOR
    SELECT CONCAT('DROP TABLE "', table_schema, '"."', table_name, '"')
    FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_name LIKE pattern;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
  OPEN cur;

  drop_loop: LOOP
    FETCH cur INTO q;
    IF done THEN
      LEAVE drop_loop;
    END IF;
    PREPARE stmt FROM @q;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
  END LOOP;
  CLOSE cur;
END;