Question

我在4个数据库中有4个表，并希望通过今天上午6:00至次日上午6:00的唯一ID和日期时间对最大值进行过滤，并输出为另一个表/ view。

我厌倦了按此要求加入餐桌。

USE PLC_WTR1
GO
SELECT  PLCTAG_PLC1_WTR1S001_PCReadJob_Tar_JobNo_Value,
MAX (Section_WTR1S001_CurrentJob_BatchLog_WeightActualProduced_Value) FROM WTR1
WHERE CAST (DateAndTime AS time) >= '05:59:00.000'
OR   CAST (DateAndTime AS time)  <= '05:59:00.000' 
GROUP BY PLCTAG_PLC1_WTR1S001_PCReadJob_Tar_JobNo_Value 

USE PLC_WTR2
GO
SELECT  PLCTAG_PLC1_WTR2S001_PCReadJob_Tar_JobNo_Value,
MAX (Section_WTR2S001_CurrentJob_BatchLog_WeightActualProduced_Value) FROM WTR2
WHERE CAST (DateAndTime AS time) >= '05:59:00.000'
OR   CAST (DateAndTime AS time)  <= '05:59:00.000' 
GROUP BY PLCTAG_PLC1_WTR2S001_PCReadJob_Tar_JobNo_Value

USE PLC_WTR3
GO
SELECT  PLCTAG_PLC1_WTR3S001_PCReadJob_Tar_JobNo_Value,
MAX (Section_WTR3S001_CurrentJob_BatchLog_WeightActualProduced_Value) FROM WTR3
WHERE CAST (DateAndTime AS time) >= ' 05:59:00.000'
OR   CAST (DateAndTime AS time)  <= '05:59:00.000' 
GROUP BY PLCTAG_PLC1_WTR3S001_PCReadJob_Tar_JobNo_Value 

USE PLC_WTR4
GO
SELECT  PLCTAG_PLC1_WTR4S001_PCReadJob_Tar_JobNo_Value,
MAX (Section_WTR4S001_CurrentJob_BatchLog_WeightActualProduced_Value) FROM WTR4
WHERE DateAndTime >= '2019-04-17 05:59:00.000'
OR   DateAndTime  <= '2019-04-18 05:59:00.000' 
GROUP BY PLCTAG_PLC1_WTR4S001_PCReadJob_Tar_JobNo_Value

Answer 1

您可以将数据库和 schema 名称放在表名称的开头。可能您想要一个union结果。另一点是，您只过滤时间部分的，因此它将带其他几天（今天除外）的行以及具有相同时间的行。

以下是如何在1个查询中使用多个数据库的示例，

select col1 from database1.dbo.table1
union all
select col1 from database2.dbo.table2

请注意，我正在使用dbo模式。

如何在多个数据库中联接multilble表

1 个答案: