Question

我正在使用MSSQL Server，我希望INNER JOIN和GROUP来自多个表的数据。但我得到了这个错误：

Column 'MyDB.dbo.USER.EmployeeID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

假设我有以下表格：

表格

    StockID        StockName
    ---------------------------
    1              StockOne
    2              StockTwo

TABLE USER

    EmployeeID    EmployeeName
    ---------------------------
    A001          ABC
    A002          ABCD

表格要求

    RequisitionID    RequestDetailsID    RequestNumber   EmployeeID
    ---------------------------------------------------------------
    1                1                   RN001           A001
    2                2                   RN001           A001
    3                3                   RN002           A002
    4                4                   RN003           A001

TABLE REQUISITION_DETAILS

    RequestDetailsID   EmployeeID    StockID
    ------------------------------------------
    1                 A001          1
    2                 A001          2
    3                 A002          1
    4                 A001          2

这是我的 SQL语法：

SELECT *

    FROM [MyDB].[dbo].[USER] A

    INNER JOIN
    [MyDB].[dbo].[REQUISITION] B
    ON
    B.EmployeeID = A.EmployeeID

    INNER JOIN  
    [MyDB].[dbo].[REQUISITION_DETAILS] C
    ON
    C.RequestDetailsID = B.RequestDetailsID

    INNER JOIN [MyDB].[dbo].[STOCK] D
    ON
    D.StockID = C.StockID

    WHERE EmployeeID = '$EpID'
    GROUP BY B.RequestNumber

预期输出

    RequestNumber   RequestDetailsID   EmployeeID    EmployeeName     StockID
    ------------------------------------------------------------------------------
    RN001           1, 2               A001          ABC              1, 2
    RN002           3                  A002          ABCD             1
    RN003           4                  A001          ABC              2

Answer 1

由于几个原因，这是一个棘手的查询。首先，SQL Server有一种相当痛苦的方法来进行聚合字符串连接。然后，您遇到了在不同表中连接请求号和员工的问题。

据我所知，您只需要两个表，requisition和requisition_details。以下查询应该接近您的需求：

select distinct r.RequestNumber, r.EmployeeId,
       stuff((select ', ' + cast(rd.RequestDetailsId as varchar(255))
              from requisition r2 join
                   requisition_details rd
                   on r2.RequestDetailsID = rd.RequestDetailsID
              where r2.RequestNumber = r.RequestNumber and r2.EmployeeId = r.EmployeeId
              for xml path ('')
             ), 1, 2, '') as RequestDetailIds,
       stuff((select ', ' + cast(rd.StockId as varchar(255))
              from requisition r2 join
                   requisition_details rd
                   on r2.RequestDetailsID = rd.RequestDetailsID
              where r2.RequestNumber = r.RequestNumber and r2.EmployeeId = r.EmployeeId
              for xml path ('')
             ), 1, 2, '') as StockIds
from requisition r

编辑：

要插入换行符，我只想使用：

       stuff((select '
' + cast(rd.RequestDetailsId as varchar(255))
              from requisition r2 join
                   requisition_details rd
                   on r2.RequestDetailsID = rd.RequestDetailsID
              where r2.RequestNumber = r.RequestNumber and r2.EmployeeId = r.EmployeeId
              for xml path ('')
             ), 1, 2, '') as RequestDetailIds,

内部连接和将多个表组合成一行

1 个答案: