数据库关联查询语句 数据表关联查询的sql语句

SELECT T3.ID,T1.TEXT,T2.TEXT,T3.OTHER FROM A T1,A T2,B T3 WHERE T1.ID=T3.PID1 AND T2.ID=T3.PID2;

数据库里面的记录是没有什么顺序可言的,只有经过一定方法的排序之后才可以有顺序,所以不存在表中第二行数据这个说法.所以如果以一个主键为排序方式的话,可以用如下方法: select top 1 * from record where (not (排序字段 in (select top 1 排序字段 from record))) 虽然看起来有点逻辑不通,但是确实能实现那种要求. sql2000下测试通过

跟my sql一样的关联,这些关联查询都是一样的,例如内联查询,左联查询 内联查询:想把用户的积分信息, 等级,都列出来,一般会出现:select * from emd_mteller t1,.

select b.出库总额as a_je,(select sum(该图书总价) as b_je from a where 出库ID=b.出库ID ) from b试试上面语句 以上语句在sqlserver中实现,查出数据后对比a_je和b_je不等的就是

select 名字 from a,bwhere a.id = b.aidand b.名字 = ＂bob＂你说的太乱了 给你个类似形式,自己补充吧a.id = b.aid就是把a,b两个表相同的列关联起来,然后再找b表中名字为bob的 也就是and后面的条件

with a as (select 1 as id, 2 as yuefen, 20 as jixiao union select 2 as id, 2 as yuefen, 20 as jixiao union select 2 as id, 3 as yuefen, 30 as jixiao union select 2 as id, 4 as yuefen, .

select name from tab1 union allselect name from tab2

哈哈select t.*,Connect_by_root id as root from (select 1 as bh, 'C' as id, 'A' as oldid from dualunion allselect 2 as bh, 'B' as id, 'Y' as oldid from dualunion allselect 3 as bh, 'X' as id, 'H' as oldid from dualunion allselect 4 as bh, 'A' as id, 'B' as oldid from dual) t start with id='C'connect by prior oldid=id

select * from Ainner join B on A.ab=B.abinner join C on A.ac=C.ac或select * from table A a,table B b ,table C cwhere a.条件=b.条件and a.条件=c.条件==========================================推荐第一种

SELECT T1.ID, T1.NAME, T2.JYSFROM T1 LEFT JOIN T2 ON T1.ID = T2.ID