How to drop multiple databases based on a prefix string

Question

example_ or e_

I want to drop all databases that match the prefix e_, so that e_database1, e_database2 and so forth are dropped.

Commands that do not work:

mysql drop database e_% mysql drop database e_*

I'm not looking for all the tables in a given database, but all the databases in a given MySQL server.

Answer 1

You could do this with a stored proc like this:

/* Start stored proc */
DELIMITER //

DROP PROCEDURE IF EXISTS db_clean_up //
CREATE PROCEDURE db_clean_up
(
)
BEGIN
declare done bit default false;
  declare deleted varchar(255);

-- Drop DBs
DECLARE cur1 CURSOR FOR SELECT 
    SCHEMA_NAME 
FROM information_schema.SCHEMATA 
WHERE SCHEMA_NAME LIKE 'db_prefix%';
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN cur1;

  createLoop: LOOP
    FETCH cur1 INTO deleted;

    IF done THEN
      LEAVE createLoop;
    END IF;

SET @query = CONCAT('DROP DATABASE `', deleted, '`;');

PREPARE stmt1 FROM @query;

EXECUTE stmt1;

END LOOP createLoop;

CLOSE cur1;

END //

delimiter ;

/* End stored proc */