Question

我正在使用3个表，尝试提取符合特定条件的列表。我需要公司表中的公司列表，这些公司有一个活跃的机会（iactive在机会表中为1）并且在类型订单或订单2的备注表中有记录。

 Companies Table
+------+------------------+
| cid  |     ccyname      |
+------+------------------+
| 1c   | Bobs Fish        |
| 2c   | Sheep Counters   |
| 3c   | Old Timers       |
| 4c   | Roasted Nuts     |
+------+------------------+

   Notes Table
+------+--------+--------+
| nid  |ntype   |cid     |
+------+--------+--------+
| 1n   | order  |3c      |
| 2n   | quest  |1c      |
| 3n   | order2 |2c      |
| 4n   | cancel |2c      |
+------+--------+--------+

Opportunities Table
+------+--------+--------+
| oid  |iactive | cid    |
+------+--------+--------+
| 1o   | 1      | 1c     |
| 2o   | 0      | 3c     |
| 3o   | 1      | 3c     |
| 4o   | 1      | 2c     |
+------+--------+--------+

通过这个例子，结果应该是：

     Results
+----------------+--------+
| ccyname        |  oid   |
+----------------+--------+
| Old Timers     | 3o     |
| Sheep Counters | 4o     |
+----------------+--------+

只有那些同时拥有积极机会和订单或订单2的公司才会给我。

我尝试过几种不同的方式，但我总是只得到一个结果或太多结果。我可以得到一些帮助吗？

这是在SQL Server 2005上。

谢谢，约翰

Answer 1

SELECT DISTINCT(ccyname), oid
FROM Companies AS c
INNER JOIN Notes AS n ON c.cid = n.cid
INNER JOIN Opportunities AS o ON c.cid = o.cid 
WHERE n.ntype IN ('order','order2')
AND o.iactive = 1;

警告：未经测试。

Answer 2

SELECT
    C.ccyname, O.oid
FROM
    Companies C
    JOIN
    Opportunities O AND O.cid = c.cid
WHERE
    O.iactive = 1
    AND
    EXISTS (SELECT * FROM Notes N
        WHERE N.ntype IN ('order', 'order2') AND N.cid = c.cid)

Answer 3

SELECT DISTINCT cid, ccyname
FROM Companies c
INNER JOIN Notes n ON n.cid = c.cid AND n.ntype = 'order2' OR n.ntype = 'order'
INNER JOIN Opportunities o ON o.cid = c.cid AND o.iactive = 1

从符合多个条件的多个表中选择

3 个答案: