更新数据库所有表和字段字符集

call changeCharSet();
drop PROCEDURE changeCharSet;
create PROCEDURE changeCharSet()
BEGIN
 DECLARE done INT DEFAULT FALSE;
 DECLARE tempsql varchar(1000);

-- 获取所有表字符集
 DECLARE rs CURSOR FOR  select   concat('ALTER TABLE ',table_name,' CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;')   from information_schema.tables where table_schema='scm' and left(table_name,3)!='act' and table_collation!='utf8mb4_general_ci';
 DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
 OPEN rs;
        read_loop: LOOP
         
         FETCH  rs INTO tempsql;
         IF done THEN
                    LEAVE read_loop;
         END IF;   
         set @exesql=tempsql;
         prepare stmt from @exesql;
         EXECUTE stmt;
         END LOOP;
    CLOSE rs;
END