select * from a right join b on a.id=b.id; select * from a j

sql 中 select * from A left join B on A.id=B.id where A.id=?如 sql函数,select count(A.abc) as sum from A left join B on A.id= select ** from A where A.id in (select id from B where ****) select distinct A.* from A,B where A.id = B.g_id and A.fwzid delete from A where a_id in (select id from B where b_id in select top 10 * from (select top 40 * from a order by id asc select * from a union select * from b 能详细说下么 select * from userinfo a inner join emp b on a.userinfoid li select * from a,b与select * from a inner join b 的取数方式和执行效率有什么 select ···fromA join B on·····和select····from A inner join B sql = "Select * from product_series order by index desc,id a sql如何取交集有这样两条sql语句select distinct id from a where id='123'se