如何使用 IN 命令保留 SQL 查询的顺序 [英] How do I preserve the order of a SQL query using the IN command

问题描述

SELECT * FROM tblItems
WHERE itemId IN (9,1,4)

按照 SQL 找到它们的顺序返回(恰好是 1、4、9)但是，我希望它们按照我在数组中指定的顺序返回.

Returns in the order that SQL finds them in (which happens to be 1, 4, 9) however, I want them returned in the order that I specified in the array.

我知道我可以用我的母语 (obj c) 对它们重新排序，但是在 SQL 中是否有一种巧妙的方法可以做到这一点?

I know I could reorder them after in my native language (obj c), but is there a neat way to do this in SQL?

这样的事情会很棒:

ORDER BY itemId (9,1,4) --    <-- this dosn't work :)

推荐答案

可能最好的方法是创建一个项目 ID 表，其中还包括一个排名顺序.然后就可以按照排名顺序加入排序了.

Probably the best way to do this is create a table of item IDs, which also includes a rank order. Then you can join and sort by the rank order.

像这样创建一个表:

 itemID rank
 9      1
 1      2
 4      3

那么您的查询将如下所示:

Then your query would look like this:

select tblItems.* from tblItems
    inner join items_to_get on
        items_to_get.itemID = tblItems.itemID
    order by rank

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