1.单表查询:select * from 表名 where id = 111
2.查询表内数据并以id排序:select * from 表名 order by id (降序:desc/升序:asc)
3.多表连接查询:select 表a.id,name...,表b.age,birthday... from 数据库A 表a,数据库A 表b where a.id = b.id
4.增:insert into 表名(‘aid’,‘aname’,‘aage’,‘abirthday’...)
5.删:delete from 表名 where id = aid
6.改:update 表名 set name=‘aname’,age=aage where id = aid