DESC和ASC作为存储过程中的参数

Question

我有以下SP用于分页新闻文章列表.正如您可能猜到的那样,@count要返回的行数@start是从中选择行的索引(按内部查询排序),@orderby表示要排序的列,并@orderdir指示是排序一个方向还是另一个方向.在添加参数之前,我的原始查询就 在这里@orderdir.

ALTER PROCEDURE [mytable].[news_editor_paginate]
    @count int,
    @start int,
    @orderby int,
    @orderdir int
AS 
BEGIN
    SET NOCOUNT ON; 
    SELECT TOP (@count) * FROM 
    (  
        SELECT ne.*,n.publishstate, 
            (CASE WHEN @orderdir = 1 THEN
                ROW_NUMBER() OVER (
                    ORDER BY                    
                        CASE WHEN @orderby = 0 THEN ne.[time] END DESC,
                        CASE WHEN @orderby = 1 THEN ne.lastedit END DESC,    
                        CASE WHEN @orderby = 2 THEN ne.title END ASC
                    )
            WHEN @orderdir = 2 THEN
                ROW_NUMBER() OVER (
                    ORDER BY                    
                        CASE WHEN @orderby = 0 THEN ne.[time] END ASC,    
                        CASE WHEN @orderby = 1 THEN ne.lastedit END ASC,
                        CASE WHEN @orderby = 2 THEN ne.title END DESC
                    )
                END
            ) AS num
            FROM news_edits AS ne
            LEFT OUTER JOIN news AS n
            ON n.editid = ne.id 
        ) 
     AS a
    WHERE num > @start
END

现在没有任何问题,但@orderby参数不起作用.如果提供1作为@orderdir参数,它将给出与我提供2作为该参数完全相同的结果.

Answer 1

行号不会在每一行上进行评估,但无论如何都是case语句,因此无论如何都会被rownum所困扰.

试试这个:

            ROW_NUMBER() OVER (
                ORDER BY                    
                    CASE WHEN @orderby = 0 AND @orderdir = 1 THEN ne.[time] END DESC,    
                    CASE WHEN @orderby = 0 AND @orderdir = 2 THEN ne.[time] END ASC,    
                    CASE WHEN @orderby = 1 AND @orderdir = 1 THEN ne.lastedit END DESC,
                    CASE WHEN @orderby = 1 AND @orderdir = 2 THEN ne.lastedit END ASC,
                    CASE WHEN @orderby = 2 AND @orderdir = 1 THEN ne.title END ASC
                    CASE WHEN @orderby = 2 AND @orderdir = 2 THEN ne.title END DESC
                )