MySQL关于重复键更新

MySQL on duplicate key update(MySQL关于重复键更新)
本文介绍了MySQL关于重复键更新的处理方法,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

如果我有这样的查询,我如何引用我已经在更新语句中给出的值,这样我就不需要插入相同的数据来再次查询?示例 我想用xxx"更新 col1 的值,但现在我需要在重复语句中再次输入xxx".无论如何在重复语句中引用这些值?

If I have query like this, how can I refer to values I have already given in update statement, so that I don't need to insert same data to query again? Example I would like to update col1 value with 'xxx', but now I need to enter 'xxx' again in duplicate statement. Is there anyway to refer those values in duplicate statement?

INSERT INTO TABLENAME(col1, col2) 
VALUES (’xxx’, ‘yyy’) 
ON DUPLICATE KEY UPDATE col1 = ‘zzz’

推荐答案

这应该可以工作并且更优雅一点:

This should work and is a little more elegant:

INSERT INTO TABLENAME(col1, col2) 
VALUES ('xxx', 'yyy') 
ON DUPLICATE KEY UPDATE col1 = VALUES(col1)

请注意,您不需要更新行的主键部分.我们知道这是一样的,因为发生了碰撞.

Note that you don't need to update the primary key part of the row. We know that's the same because there was a collision.

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