UNION和ORDER BY的结果很奇怪 [英] Weird result with UNION and ORDER BY

查看：109 发布时间：2020/8/14 5:16:49 mysql union

本文介绍了UNION和ORDER BY的结果很奇怪的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

我有这个查询(简体):

I have this query (simplified):

SELECT score FROM tbl WHERE id = xx ORDER BY score DESC;

它可以正常工作.现在，我向该查询添加一个像这样的UNION:

And it works correctly. Now I add to this query an UNION like this:

(SELECT score FROM tbl WHERE id = x ORDER BY score DESC)
   UNION
(SELECT score FROM tbl WHERE id = y)

现在，第一个查询的所有第一个结果集都被弄乱了，不遵守ORDER BY score DESC

Now all the first result-set of the first query is messed up not respecting the ORDER BY score DESC

从tbl中选择分数，id = x 联盟从tbl WHERE id = y中选择分数

SELECT score FROM tbl WHERE id = x UNION SELECT score FROM tbl WHERE id = y

按分数DESC排序；

ORDER BY score DESC;

只需在末尾添加订单即可.它将应用于整个结果集.如果要区分结果，请添加订单栏，如下所示:

just add the order by to the end. it will apply to the entire result set. If you want to differentiate the result add an order col like so:

选择1作为order_col，在tbl WHERE id = x时得分联盟选择2作为order_col，从tbl WHERE id = y得分

SELECT 1 as order_col, score FROM tbl WHERE id = x UNION SELECT 2 as order_col, score FROM tbl WHERE id = y

ORDER BY order_col，得分DESC；

ORDER BY order_col ,score DESC;

这篇关于UNION和ORDER BY的结果很奇怪的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

查看全文