sql 常用语句

#查询
select * from t_user where id=1;
关联查询
select * from a left join b on a.id=b.id;
select * from a right join b on a.id=b.id;
select * from a inner join b on a.id=b.id;

#union结果集合用
select id,name from a where id=3
union
select id,name from b where id=4;
#嵌套
select * from (select * from b) where name='linux'l;
select * from t_user where id in (select id from t_id);
select * from t_user where (id,name) in (select id,name from t_id);
#having二次筛选
select * from t_user where id =4 group by name having count(name)>3;
#between
select * from t_user where id between 1 and 10;