两表联查sql语句 sql查询两个表的数据

多表查询分为 内、外连接 外连接分为左连接(left join 或left outer join)、右连接(. *fron table1 join table2 on table1.条件列名 = table2.条件列名 返回符合匹配条件的两表列 .

把两个表都选上,选择你要的字段,然后在条件里面把关联的字段条件加上,例如下. 发布时间,这条语句并不一定可用,要对照你的表结构.如果有不清楚可以给我发信.

select kd_to as 目的地,'共计' + cast(count(kd_to) as nvarchar) + '单' as 总数 from kuaidi inner join towhere on kuaidi.to_type=towhere.to_type group by kd_to

select kd_to as 目的地, count(*) as 总数 from kuaidi, towhere where kuaidi.to_type = towhere.to_type group by kd_to order by count(*) desc

select A.MEDIID,B.PRICE from A,B where a.MEDIID=B.MEDIID

select a.*,b.* from a inner join b on a.id=b.字段2 order by a.字段3 desc,b.字段4 desc

select a.no,a.name,b.subid,b.subname,c.score from a,b,c where a.no = c.no and b.subid = c.subid ;

select a.*,c.* from a,c where a.e=c.e and c.d=1 and a.b=10

SELECT p.*,u.U_Name FROM Users AS u LEFT JOIN Posts AS p ON p.User_ID=u.User_ID WHERE u.User_ID=2上述的例子查出Users表中User_ID=2和Posts表中User_ID=2的那条记录,并例出Users表中的U_Name字段和Posts表的所有字段你也可以查出User_Name='admin'的,或者,Post_ID=5的,以此类推.

select * from tableA where id=1 select * from tableA where id=2 你说的好像要加一个字段 parent_id这样才能连接上吧!!