19.3.25 sql查詢語句

1.單表查詢：select * from 表名 where id = 111

2.查詢表內數據並以id排序：select * from 表名 order by id (降序:desc/升序:asc)

3.多表鏈接查詢：select 表a.id,name...,表b.age,birthday... from 數據庫A 表a，數據庫A 表b where a.id = b.id

4.增：insert into 表名（‘aid’，‘aname’，‘aage’，‘abirthday’...）

5.刪：delete from 表名 where id = aid

6.改：update 表名 set name=‘aname’，age=aage where id = aid