Question

SELECT *
FROM
    TableName
WHERE
ORDER BY 
    CASE @OrderByColumn
    WHEN 1 THEN Forename
    WHEN 2 THEN Surname
    END;

我有一个如上所述的声明，让我动态选择如何订购查询结果。但是，如何指定我要订购的Forename DESC和姓氏ASC？

Answer 1

您需要将ORDER BY拆分为两部分：

SELECT *
FROM
    TableName
WHERE
ORDER BY 
    (CASE @OrderByColumn
    WHEN 1 THEN Forename
    END) DESC -- Forename --> descending
,   (CASE @OrderByColumn
    WHEN 2 THEN Surname
    END) ASC -- Surname --> ascending

Answer 2

order by中需要两个子句：

ORDER BY (CASE WHEN @OrderByColumn = 1 and @Dir = 'ASC' THEN Forename
               WHEN @OrderByColumn = 2 and @Dir = 'ASC' THEN Surname
          END) ASC,
         (CASE WHEN @OrderByColumn = 1 and @Dir = 'DESC' THEN Forename
               WHEN @OrderByColumn = 2 and @Dir = 'DESC' THEN Surname
          END) DESC

Answer 3

另一个例子：

SELECT * FROM dbo.Employee
ORDER BY 
 CASE WHEN Gender='Male' THEN EmployeeName END Desc,
 CASE WHEN Gender='Female' THEN Country END ASC

更多详情...... http://codechef4u.com/post/2015/04/07/order-by-clause-with-case-expressions-case-statement

具有Desc / Asc排序的Order By子句的Case语句

3 个答案: