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SQL Server等同于GROUP_CONCAT（）[重复]

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这个问题在这里已有答案：

我有这个数据库：

enter image description here

我需要为 each 客户端获取以下数据：

  • 客户名称

  • Contract 名称

  • 项目

  • 从当月第一天到当月最后一天记录项目时间的员工

  • 本月每位员工记录的总小时数

  • 员工比率

  • 每位员工的总费用（即员工费率x员工工时）

  • 每个 Contract 的结算联系人[姓名，地址]

到目前为止我有以下查询，但我需要实现MySQL的GROUP_CONCAT（）的MSSQL版本

SELECT 

Cl.LegalName AS ClientNames,
Cr.ContractDesc AS ContractNames,
P.ProjectName AS ProjectNames,
( E.FirstName + ' ' + E.LastName ) AS EmployeeNames,
SUM( WH.HoursWorked ) AS TotalHours, 
( SUM( WH.HoursWorked ) * BR.Rate ) AS TotalCharges, 
( Ca.FirstName + Ca.LastName + ', ' + Ca.AddrLine1 ) AS BillingContacts

FROM Clients Cl
JOIN Contracts Cr
ON( Cl.ClientID = Cr.ClientID )

JOIN Projects P 
ON( Cr.ContractID = P.ContractID )

JOIN EmployeesProjects EP
ON( P.ProjectID = EP.ProjectID )

JOIN Employees E 
ON( EP.EmpID = E.EmpID )

JOIN WorkHours WH
ON( E.EmpID = WH.EmpID )

JOIN BillingRates BR
ON( E.TitleID = BR.TitleID ) AND ( E.Level = BR.Level )

JOIN ContractsContacts CC
ON( Cr.ContractID = CC.ContractID )
JOIN Contacts Ca
ON( CC.ContactID = Ca.ContactID )

WHERE WH_Month = 4
AND WH_Year = 2013

当我开始关注this示例时，我到达此处并停止，因为我意识到我无法从其他子查询（ProjectNames）引用表别名（Cr） .

SELECT 
Cl.LegalName AS ClientNames, 
(
    SELECT ContractDesc + ', '
    FROM Contracts Cr
    WHERE Cl.ClientID = Cr.ClientID 
    FOR XML PATH('')
) ContractNames,
(
    SELECT ProjectName + ', '
    FROM Projects P
    WHERE Cr.ContractID = P.ContractID
    FOR XML PATH('')
) ProjectNames


FROM Clients Cl

我到底该怎么做呢？

sql sql-server join string-aggregation

3 回答

  • 1

    试试 CROSS APPLY 来做这个：

    例如：

    SELECT Cl.LegalName AS ClientNames,
B.ContractDesc AS ContractNames,
P.ProjectName AS ProjectNames,
( E.FirstName + ' ' + E.LastName ) AS EmployeeNames,
SUM( WH.HoursWorked ) AS TotalHours, 
( SUM( WH.HoursWorked ) * BR.Rate ) AS TotalCharges, 
( Ca.FirstName + Ca.LastName + ', ' + Ca.AddrLine1 ) AS BillingContacts

FROM Clients Cl
JOIN Contracts Cr ON( Cl.ClientID = Cr.ClientID )
JOIN Projects P ON( Cr.ContractID = P.ContractID )
JOIN EmployeesProjects EP ON( P.ProjectID = EP.ProjectID )
JOIN Employees E ON( EP.EmpID = E.EmpID )
JOIN WorkHours WH ON( E.EmpID = WH.EmpID )
JOIN BillingRates BR ON( E.TitleID = BR.TitleID ) AND ( E.Level = BR.Level )
JOIN ContractsContacts CC ON( Cr.ContractID = CC.ContractID )
JOIN Contacts Ca ON( CC.ContactID = Ca.ContactID ) 
CROSS APPLY (
    SELECT Cr1.ContractDesc + ', '
    FROM Contracts Cr1
    WHERE Cl.ClientID = Cr1.ClientID 
    FOR XML PATH('')
) B (ContractDesc)
WHERE WH_Month = 4 AND WH_Year = 2013
    回复于
  • 1

    这样做

    SELECT Cl.LegalName AS ClientNames,
   ContractNames
   FROM Clients Cl
    cross apply 
   (SELECT Cr1.ContractDesc + ', '
    FROM Contracts Cr1
      WHERE Cl.ClientID = Cr1.ClientID  For XML PATH(''))a1 (ContractNames)
    回复于
  • 0

    STRING_AGG几乎等同于MySQL中的GROUP_CONCAT . 请参阅Microsoft的官方文档here

    请注意，STRING_AGG不允许文本类型，因此如果要在文本字段上连接，则需要转换为NVARCHAR .

    例：

    STRING_AGG(CONVERT(NVARCHAR(2000), your_text_field_name), ',')
    回复于

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