【sql】個人筆記

個人筆記

1. 查詢數據庫表

select table_name ,create_time , engine, table_collation, table_comment from information_schema.tables 
where table_schema = (select database()) and table_name like '%%' order by create_time desc 

2. 查詢數據庫表的個數

SELECT COUNT(*) from information_schema.tables where table_schema = (select database())

3. 修改最大數據包

SET GLOBAL max_allowed_packet = 2*1024*1024*10;

4. 查看最大數據包

SHOW VARIABLES LIKE '%max_allowed_packet%';

5. 心跳

SELECT USER();