MySQL存储过程：删除带like条件的表名

delimiter //

CREATE PROCEDURE drop_table_like(IN table_prefix varchar(64), IN username varchar(256))
BEGIN
    DECLARE tname varchar(128) default '';
    DECLARE not_found INT DEFAULT 0;
    DECLARE cur_tnames cursor FOR SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = username and table_name like table_prefix;
    -- concat("'", table_prefix, "%'");
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET not_found = 1;
    DECLARE EXIT HANDLER FOR SQLEXCEPTION ROLLBACK; 
    OPEN cur_tnames;
    WHILE not_found = 0 DO
        FETCH cur_tnames INTO tname;
        IF NOT not_found THEN
            -- select tname;
            set @sql = concat('DROP TABLE ', tname);
            prepare stmt from @sql;
            execute stmt;
            deallocate prepare stmt;
        END IF;
    END WHILE;
    CLOSE cur_tnames;
END
//

mysql> call drop_table_like('taba%', 'foo')//
Query OK, 0 rows affected (0.17 sec)

 要说的是，前边使用concat("'", table_prefix, "%'");

 作为cursor的定义条件，居然不能用。或许mysql不认可这种条件定义。