Question

我有两个表通过一对多关系连接（表A中的一个记录将在表B中有多个连接到它的记录）。作为参考，表A保留了事件记录，而表B保存了表A中事件进展的附注。

表格：

表A：

SELECT [IncID]
      ,[TechId]
      ,[TechName]
      ,[Complete]
      ,[StartDateTime]
      ,[CompleteDateTime]
      ,[Subject]
      ,[Description]
      ,[Resolution]
  FROM [TableA]

表B：

SELECT TOP 1000 [IncHistID]
      ,[IncID]
      ,[TechID]
      ,[TechName]
      ,[NoteDate]
      ,[NoteTime]
      ,[Description]
      ,[ContactName]
      ,[RowNum]
  FROM [TableB]

两个表通过[IncID]列连接。我希望能够通过TableB的NoteDate Column订购TableA。

我使用以下查询以所需顺序获得了TableB：

SELECT [IncID]
        ,Max(Notedate) as NoteDate
  FROM [PDSupport].[dbo].[vwWebIncidentsHist3]
  Group by IncID
  Order By  Notedate Desc

Answer 1

假设您在两个表中都有IncID索引，使用连接然后简单排序似乎是最有效和最标准的方法......

SELECT A.[IncID]
  ,A.[TechId]
  ,A.[TechName]
  ,A.[Complete]
  ,A.[StartDateTime]
  ,A.[CompleteDateTime]
  ,A.[Subject]
  ,A.[Description]
  ,A.[Resolution]
  ,max(B.noteDate) mNotedate
FROM tableA A
LEFT JOIN tableB B
 on A.IncID=B.IncID
GROUP BY A.[IncID]
  ,A.[TechId]
  ,A.[TechName]
  ,A.[Complete]
  ,A.[StartDateTime]
  ,A.[CompleteDateTime]
  ,A.[Subject]
  ,A.[Description]
  ,A.[Resolution]
ORDER BY mNoteDate desc

按另一个子表排序表

1 个答案: