Question

我在JOINS上发了一篇很棒的帖子，What is the difference between "INNER JOIN" and "OUTER JOIN"?，但我认为这对我的问题没有帮助。

我想将两个select语句组合成一个select语句AND，使其对任何要查询的数据库都有效。

这就是我所拥有的

SELECT
(SELECT COUNT(*) 
                        FROM dbo.sem_computer, [dbo].[V_SEM_COMPUTER], dbo.IDENTITY_MAP, dbo.SEM_CLIENT,dbo.SEM_AGENT,dbo.PATTERN
                        WHERE [dbo].[V_SEM_COMPUTER].COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND dbo.SEM_CLIENT.GROUP_ID = IDENTITY_MAP.ID
                        AND dbo.SEM_CLIENT.COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND SEM_COMPUTER.COMPUTER_ID = dbo.SEM_AGENT.COMPUTER_ID
                        AND dbo.PATTERN.PATTERN_IDX = dbo.SEM_AGENT.PATTERN_IDX
                        AND Name like '%Staten Island%'
                        AND dbo.SEM_AGENT.AGENT_VERSION LIKE '11.%'
                        AND dbo.SEM_COMPUTER.OPERATION_SYSTEM LIKE 'Windows%') AS 'Windows-SEP-11',
(SELECT COUNT(*) 
                        FROM dbo.sem_computer, [dbo].[V_SEM_COMPUTER], dbo.IDENTITY_MAP, dbo.SEM_CLIENT,dbo.SEM_AGENT,dbo.PATTERN
                        WHERE [dbo].[V_SEM_COMPUTER].COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND dbo.SEM_CLIENT.GROUP_ID = IDENTITY_MAP.ID
                        AND dbo.SEM_CLIENT.COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND SEM_COMPUTER.COMPUTER_ID = dbo.SEM_AGENT.COMPUTER_ID
                        AND dbo.PATTERN.PATTERN_IDX = dbo.SEM_AGENT.PATTERN_IDX
                        AND Name like '%Staten Island%'
                        AND dbo.SEM_AGENT.AGENT_VERSION LIKE '12.%'
                        AND dbo.SEM_COMPUTER.OPERATION_SYSTEM LIKE 'Windows%') AS 'Windows-SEP-12',
(SELECT COUNT(*) 
                        FROM dbo.sem_computer, [dbo].[V_SEM_COMPUTER], dbo.IDENTITY_MAP, dbo.SEM_CLIENT,dbo.SEM_AGENT,dbo.PATTERN
                        WHERE [dbo].[V_SEM_COMPUTER].COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND dbo.SEM_CLIENT.GROUP_ID = IDENTITY_MAP.ID
                        AND dbo.SEM_CLIENT.COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND SEM_COMPUTER.COMPUTER_ID = dbo.SEM_AGENT.COMPUTER_ID
                        AND dbo.PATTERN.PATTERN_IDX = dbo.SEM_AGENT.PATTERN_IDX
                        AND Name like '%Staten Island%'
                        AND dbo.SEM_AGENT.AGENT_VERSION LIKE '11.%'
                        AND dbo.SEM_COMPUTER.OPERATION_SYSTEM LIKE 'Mac%') AS 'Mac-SEP-11',
(SELECT COUNT(*)
                        FROM dbo.sem_computer, [dbo].[V_SEM_COMPUTER], dbo.IDENTITY_MAP, dbo.SEM_CLIENT,dbo.SEM_AGENT,dbo.PATTERN
                        WHERE [dbo].[V_SEM_COMPUTER].COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND dbo.SEM_CLIENT.GROUP_ID = IDENTITY_MAP.ID
                        AND dbo.SEM_CLIENT.COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
                        AND SEM_COMPUTER.COMPUTER_ID = dbo.SEM_AGENT.COMPUTER_ID
                        AND dbo.PATTERN.PATTERN_IDX = dbo.SEM_AGENT.PATTERN_IDX
                        AND Name like '%Staten Island%'
                        AND dbo.SEM_AGENT.AGENT_VERSION LIKE '12.%'
                        AND dbo.SEM_COMPUTER.OPERATION_SYSTEM LIKE 'Mac%')  AS 'Mac-SEP-12'

如何缩小此SQL语句？即使我使用内部联接（我正在处理），这个语句是处理器密集型的（更不用说它看起来效率很低）

Answer 1

您可以使用data: Array[5]执行此操作。

还使用正确的Conditional Aggregate语法来连接两个表而不是旧式逗号分隔连接。将过滤器保留在INNER JOIN子句

中

Where

Answer 2

在提供答案的基础上，我认为更优雅的解决方案是将过滤值保存在单独的表中（与数据分开的逻辑）。

但是，这只有在条件不相交时才会起作用（一对值最多会达到一个条件），否则多次＆＃34;命中＆＃34>将计入更多选择。

INSERT INTO dbo.AgentAndOsFilter (AgentVersion, Os)
VALUES ('11.%', 'Windows%'), ('12.%', 'Windows%'), ('11.%', 'Mac%'), ('12.%', 'Mac%')

这可以使用您的过滤对填充：

SELECT F.Id, Count(1) Cnt
FROM   dbo.sem_computer
       INNER JOIN [dbo].[V_SEM_COMPUTER]
               ON [dbo].[V_SEM_COMPUTER].COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
       INNER JOIN dbo.SEM_AGENT
               ON SEM_COMPUTER.COMPUTER_ID = dbo.SEM_AGENT.COMPUTER_ID
       INNER JOIN dbo.SEM_CLIENT
               ON dbo.SEM_CLIENT.COMPUTER_ID = SEM_COMPUTER.COMPUTER_ID
       INNER JOIN dbo.IDENTITY_MAP
               ON dbo.SEM_CLIENT.GROUP_ID = IDENTITY_MAP.ID
       INNER JOIN dbo.PATTERN
               ON dbo.PATTERN.PATTERN_IDX = dbo.SEM_AGENT.PATTERN_IDX
       INNER JOIN dbo.AgentAndOsFilter F 
               ON dbo.SEM_AGENT.AGENT_VERSION LIKE F.AgentVersion 
                   AND dbo.SEM_COMPUTER.OPERATION_SYSTEM LIKE F.Os
WHERE  Name LIKE '%Staten Island%' 
GROUP BY F.Id

查询可能如下所示：

{{1}}

此解决方案的另一个优点是配置更改（代理的新版本，新操作系统）只是意味着更改表中的某些记录。

简化MS SQL语句

2 个答案: