增加数据
insert into wyx(xh,nl,xb,sfzh,zcrq)values(0422,28,男,210623198711111111,2016-8-19);
删除数据
delete from wyx where name=();
修改数据
update 表名 set name='liudehua' where 条件
查询数据
select distinct xm,xb count(*) from 表名 where xh in () and name not in () group by bj having count (*)>5 order by xm desc limit(0,5);
select * from A inner join B on A.xh=B.xh inner join C on C.xh=B.xh where 条件;
select * from A left join B on A.xh=B.xh where 条件;
select * from A right join B on A.xh=B.xh where 条件;