使用CASE WHEN时，ORDER BY不起作用，但没有它，则可以工作吗？

Question

我有以下选择语句，在该语句中，我尝试以特定方式（尤其是部门的层次结构）对结果进行排序。但是，当我添加案例时，我的ORDER BY停止工作并给我一个错误：

如果语句包含UNION，INTERSECT或EXCEPT运算符，则ORDER BY项目必须出现在选择列表中。

我不知道为什么会这样，因为我在每个SELECT语句中都选择了所有内容。

Select * FROM AccountAdminTable Where CollegeCode = 'A10' AND AdminLevel LIKE 'Account Administrator'
Union
Select * FROM AccountAdminTable Where CollegeCode = 'A10' AND AdminLevel LIKE 'Department Head/Director'
Union
Select * FROM AccountAdminTable Where CollegeCode = 'A10' AND AdminLevel LIKE 'Dean/Vice President'
Order By AdminLevel ASC

这不起作用：

Select * FROM AccountAdminTable Where CollegeCode = 'A' AND AdminLevel LIKE 'Account Administrator'
Union
Select * FROM AccountAdminTable Where CollegeCode = 'A' AND AdminLevel LIKE 'Department Head/Director'
Union
Select * FROM AccountAdminTable Where CollegeCode = 'A' AND AdminLevel LIKE 'Dean/Vice President'
Order By Case
    When AdminLevel = 'Account Administrator' Then 1
    When AdminLevel = 'Department Head/Director' Then 2
    When AdminLevel = 'Dean/Vice President' Then 3
    Else 4 End ASC

任何帮助是极大的赞赏！以下是一些示例数据。

College Code| AdminLevel               | Name
A           | Account Administrator    | Bob
A           | Department Head/Director | Tim
A           | Dean/Vice President      | Jeff
B           | Account Administrator    | Gary
B           | Department Head/Director | Phil
B           | Dean/Vice President      | John
C           | Account Administrator    | Bill
C           | Account Administrator    | Larry

Answer 1

您知道，这里真的不需要使用UNION。由于您所有的SELECTS都来自同一张表，因此您可以这样做（请注意，下面我的伪代码中使用的缩写。显然，您的代码中使用了正确的值）：

Select * FROM AccountAdminTable 
Where CollegeCode = 'A'
AND AdminLevel IN ('Account Administrator','Dept HD','Dean/VP')
ORDER BY CASE {Your CASE Expression}