三个表的内连接查询，估计应是，还要老师们判断

[sdmc01]

T1 表 主键code

code   ss
0001  5
0002  9
0003  10
0004  11

T2表 主键 pakcode 注：这个表code 有重复的，当code有重复的时，pakcode不与其他表连接

pakcode  code  dd 
A01          0002   11
A02          0003   22
A02          0003   55
A05          0004   66
A06          0005   77

T3表 主键code

code   sale
0001       5
0002       9
0003      10
0004      11
A01           5
A02           10
A05           6
A06           9

查询结果,我估计应是内连接吧

code    sale
A01      5
A05      6

非常感谢！

[shoppo0505]

楼主是来给我们出考题的么？还是来文问题？ 给我们数据，来整理出链接规则？

[sdmc01]

引用 1 楼 shoppo0505 的回复:

楼主是来给我们出考题的么？还是来文问题？ 给我们数据，来整理出链接规则？

文字说的过多，反而容易乱，已经列出了主键，高手自然看结果更容易懂吧，而且估计是内连接

[zhouyuehai1978]

T2表去掉重复的，然后joinT1表和T3表，取T2表的PakCode和T3表的Sale

[zhouyuehai1978]

--测试数据
IF NOT OBJECT_ID(N'Tempdb..#T1') IS NULL
    DROP TABLE #T1
IF NOT OBJECT_ID(N'Tempdb..#T2') IS NULL
    DROP TABLE #T2
IF NOT OBJECT_ID(N'Tempdb..#T3') IS NULL
    DROP TABLE #T3        
GO
CREATE TABLE #T1
(
	Code  VARCHAR(20),
	ss     VARCHAR(20)
)
INSERT #T1
SELECT '0001','5'UNION ALL
SELECT '0002','9'UNION ALL
SELECT '0003','10'UNION ALL
SELECT '0004','11'
CREATE TABLE #T2
(
	pakcode  VARCHAR(20),
	code     VARCHAR(20),
	dd	VARCHAR(20)
)
INSERT #T2
SELECT 'A01','0002','11'UNION ALL
SELECT 'A02','0003','22'UNION ALL
SELECT 'A02','0003','55'UNION ALL
SELECT 'A05','0004','66'UNION ALL
SELECT 'A06','0005','77'
CREATE TABLE #T3
(
	Code  VARCHAR(20),
	sale     VARCHAR(20)
)
INSERT #T3
SELECT '0001','5' UNION ALL
SELECT '0002','9' UNION ALL
SELECT '0003','10' UNION ALL
SELECT '0004','11' UNION ALL
SELECT 'A01','5' UNION ALL
SELECT 'A02','10' UNION ALL
SELECT 'A05','6' UNION ALL
SELECT 'A06','9' 
GO
--测试数据结束
--SELECT * FROM   #T1 AS t1
--SELECT * FROM   #T2 AS t2
--SELECT * FROM   #T3 AS t3;
WITH new_t2 AS (
         SELECT t.pakcode,t.code
         FROM   #T2 AS t
         WHERE  NOT EXISTS (
                    SELECT t2.code
                    FROM   #T2 AS t2
                    WHERE  t2.code = t.code
                    GROUP BY
                           t2.code
                    HAVING COUNT(*) > 1
                )
     )
SELECT t2.pakcode,
       t3.sale
FROM   #T1          AS t
       JOIN new_t2  AS t2
            ON  t.Code = t2.code
       JOIN #T3     AS t3
            ON  t2.pakcode = t3.Code

[sdmc01]

非常谢谢！！