MS Sql: Conditional ORDER BY ASC/DESC 问题 [英] MS Sql: Conditional ORDER BY ASC/DESC Question

问题描述

我想让我的查询中的排序有条件，所以如果它满足条件，它应该按降序排序

I want to to make to make the ordering in my query conditional so if it satisfiess the condition it should be ordered by descending

例如:

SELECT * FROM Data ORDER BY SortOrder CASE WHEN @Direction = 1 THEN DESC END

推荐答案

不要改变 ASC 或 DESC，改变正在排序的事物的符号:

Don't change the ASC or DESC, change the sign of the thing being sorted-by:

SELECT * FROM table 
ORDER BY 
CASE WHEN @Direction = 1 THEN -id else id END asc;

OP 询问:

伙计们，我不是 SQL 专家，请解释一下 id 和 -id 是什么意思，它控制排序方向吗?

Guys, I am not the SQL Expert, please explain me what means the id and -id, does it controls the ordering direction?

id 就是您要排序的任何列；-id 只是那个的否定，id * -1.如果按多列排序，则需要对每一列求反:

id is just whatever column you're sorting by; -id is just the negation of that, id * -1. If you're sorting by more than one column, you'll need to negate each column:

SELECT * FROM table 
ORDER BY 
CASE WHEN @Direction = 1 THEN -id else id END 
CASE WHEN @Direction = 1 THEN -othercolumn else othercolumn END ;

如果您按非数字列排序，则需要找到使该列为负"的表达式；编写一个函数来做到这一点可能会有所帮助.

If you're ordering by a non numeric column, you'll need to find an expression that makes that column "negative"; writing a function to do that may help.

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