Question

我在Windows7上使用MS SQL Server 2014 我有一个名为＆＃34; PollingStatus ＆＃34;。的表以下查询：

SELECT DeviceIP
      ,ServiceStatus
      ,ReportedErrors
FROM PollingStatus

...给出了一些这样的信息：

DeviceIP   |    ServiceStatus   |   ReportedErrors   
10.20.1.1  |          0         |         0     
10.20.1.2  |          0         |         0

在另一个名为＆＃34; DeviceProperties ＆＃34;的表中我有类似的东西：

DeviceIP   |    DeviceType      |    SwVersion   
10.20.1.1  |          3         |       800     
10.20.1.1  |          2         |       802     
10.20.1.1  |          1         |       804     
10.20.1.2  |          2         |       800     
10.20.1.2  |          3         |       801     
10.20.1.2  |          2         |       806

我需要的是一个查询来获得这样的东西：

DeviceIP   |  ServiceStatus  |  ReportedErrors  | DeviceType | SwVersion  
10.20.1.1  |        0        |        0         |    1       |   804  
10.20.1.2  |        0        |        0         |    2       |   806

ie：与我现有的查询相比，我想从第二个表＆＃34; DeviceProperties中获得DeviceType和设备的最大 SwVersion ＆＃34 ;.

Answer 1

这应该足够了

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Route::get('/dashboard2', function () {
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});

Answer 2

Select 
D.DeviceIP,
D.ReportedErrors,
D.ServiceStatus,
DD.DeviceType,
DD.SwVersion 
from @Device D
INNER JOIN (Select 
                DeviceIP,
                MIN(DeviceType)DeviceType,
                MAX(SwVersion)SwVersion 
                        from  @Devicetype
GROUP BY DeviceIP )DD
ON D.DeviceIP = DD.DeviceIP

Answer 3

尝试：

    SELECT 
        ps.DeviceIp, 
        ps.ServiceStatus, 
        ps.ReportedErrors, 
        dp.DeviceType, 
        Max(dp.SwVersion)
    FROM PollingStatus ps
    INNER JOIN DeviceProperties dp ON dp.DeviceIp = ps.DeviceIp
    GROUP BY ps.DeviceIp, ps.ServiceStatus, ps.ReportedErrors, dp.DeviceType;

除此之外，如果您希望一个表中的记录在另一个表中没有对应，则使用不同类型的连接。

SQL：如何从表中获取单个查询信息并从另一个表中获取聚合信息？

3 个答案: