本文介绍了MYSQL 选择两列中的 DISTINCT 值的处理方法，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！
问题描述
我想在数据库中选择不同的值.让我通过一个简单的例子来告诉你.
I want to select distinct values in a database. Let me run you through a quick example.
表格:
foo bar
--- ---
a c
c f
d a
c a
f c
a c
d a
a c
c a
f c
好吧，假设我的 SQL 是 SELECT DISTINCT foo, bar from table.这些是我的结果:
Right, let's say my SQL is SELECT DISTINCT foo, bar from table. These are my results:
foo bar
--- ---
a c
c f
d a
c a
f c
然而，问题是存在 a c/c a 的重复，只是它们的顺序不同.我不想选择这些，我想要两列的不同值，请帮忙！
However the problem is is that there are repetitions of a c / c a just that they are in a different order. I don't want to select these, I want distinct values from both columns, please help!
推荐答案
非常非常邪恶 &邪恶:
very very wicked & evil:
select distinct
least(foo, bar) as value1
, greatest(foo, bar) as value2
from table
这篇关于MYSQL 选择两列中的 DISTINCT 值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编程学习网！
本站部分内容来源互联网,如果有图片或者内容侵犯您的权益请联系我们删除！