Question

好的。我已经设置了一小组样本表。我只是举个例子，因为这是我传达这个问题的最佳方式。

Certs表：

WorkerId    Name                             Version
----------- -------------------------------- -----------
1           Construction                     1
1           Construction                     2
1           Demolition                       1
1           Fusion                           1
5           Fusion                           1
4           Demolition                       1
4           Demolition                       2

CertDesc表（版本，名称形式主键）：

Name                             Version     Description
-------------------------------- ----------- -----------------------------------------------------------------------------------------
Construction                     1           Basic Construction -- Required for all construction workers.
Construction                     2           Full Construction -- Required for all construction managers.
Demolition                       1           Demolition -- Explosives --  Required for demolition managers.
Fusion                           1           Fusion System Control -- Includes catastrophic super-criticality recovery.
Demolition                       2           Large Scale Demolition -- Basic fission knowledge with full chemical cert.

现在。我想获得所有CertDesc行的列表，以便WorkerId 1没有该证书。对于X = 1，我应该只获得拆迁2。

以下几乎是那些对我来说最好的查询：

Select Distinct d.Name, d.Version, d.Description
From CertDesc d join Certs c on d.Name = c.Name and d.Version = c.Version
Where d.Name NOT IN (Select c2.Name
    From Certs c2
    Where c2.WorkerId = 1)

此查询返回零行。问题是，无论版本号如何，都会排除拆除行。我想要的是使用IN与元组：

Select Distinct d.Name, d.Version, d.Description
From CertDesc d join Certs c on d.Name = c.Name and d.Version = c.Version
Where (d.Name, d.Version) NOT IN (Select c2.Name, c2.Version)
    From Certs c2
    Where c2.WorkerId = 1)

不幸的是，这在SQL Server中无效。有人知道一个很好的方法吗？

Answer 1

SELECT  *
FROM    CertDesc cd
WHERE   NOT EXISTS
        (
        SELECT  NULL
        FROM    Certs c
        WHERE   c.WorkerId = 1
                AND c.name = cd.name
                AND c.version = cd.version
        )

，或者，如果name和version足够，只需：

SELECT  name, version
FROM    CertDesc
EXCEPT
SELECT  name, version
FROM    Certs
WHERE   WorkerId = 1

编辑：后一个查询仅适用于SQL-Server 2005。

Answer 2

这样的事情会起作用吗？

 select c.WorkerId, c.Name as workername, cd.version, 
       cd.name as certificatename
  from certs as c
 cross join certdesc as cd 
 where cd.version <> c.version
   and cd.name <> c.name
 order by c.workerid

比较：

select c.WorkerId, c.Name as workername, cd.version, 
       cd.name as certificatename
  from certs as c
 cross join certdesc as cd 
 where cd.version = c.version
   and cd.name = c.name
 order by c.workerid

SQL - 在多行键上连接的表上使用IN

2 个答案: