所有的表都增加字段：
-- table_schema 指定数据库
SELECT table_name,substr(table_name,1,3),
CONCAT('alter table ' ,table_name ,' add update_user varchar(50);') as f
FROM information_schema.tables
WHERE table_schema = 'gzgs_202230920' ;
所有的表修改编码：
SELECT CONCAT("ALTER TABLE `", TABLE_NAME,"` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;") AS target_tables
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA="bladex_laster"
and TABLE_NAME not like 'act%'
and TABLE_NAME not like 'view%'
and TABLE_NAME not like 'lab%'
