列“*”在选择列表中无效，因为它既不包含在聚合函数中，也不包含在 GROUP BY 子句中答案

【问题标题】：Column '*' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause列“*”在选择列表中无效，因为它既不包含在聚合函数中，也不包含在 GROUP BY 子句中
【发布时间】：2014-05-14 17:02:23
【问题描述】：

我有如下查询

select a.EmployeeName, 

STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
from 
EmployeeTable a
where a.EmployeeID = 144025
group by EmployeeName, Departments

但是当我执行上面的sql时，出现了错误：

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

预期结果：

上面的sql有什么问题？

【问题讨论】：

标签： sql sql-server aggregate-functions

【解决方案1】：

使用子查询

SELECT Z.EmployeeName,Z.Departments FROM (
   select a.EmployeeName, 

   STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
  from 
  EmployeeTable a
  where a.EmployeeID = 144025
) Z
group by Z.EmployeeName, Z.Departments

【讨论】：

【解决方案2】：

我认为这是因为 group by 子句中缺少 EmployeeID 列。子查询中指定的列也应该包含在 group by 子句中。

请尝试：

select a.EmployeeName, 

STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
from 
EmployeeTable a
where a.EmployeeID = 144025
group by EmployeeID, EmployeeName, Departments

【讨论】：