mysql更新增量int字段为空 [英] mysql update increment int field that is null

问题描述

我有一个非常大的表，其中有两个INT列，这些列在Default上为空.这是一个问题，因为它们是INT字段，因此如果最初将它们设置为0，在很多情况下都会有帮助.

I have a very large table with two INT columns that are null on Default. This is a problem because since they are INT fields, it would help in many cases if they were originally set to 0.

所以我的问题是，有没有办法像这些字段一样对这些字段进行UPDATE和INCREMENT(+1)(默认为空)?顺便说一句..到目前为止我还没有运气，似乎增量仅在默认值= 0时有效

So my questions are, is there a way I can UPDATE and INCREMENT(+1) these fields while they are like this (null on Default)? BTW.. I didn't have luck so far, it seems increment only works when the default=0

.. or是将默认值从null更改为无"的唯一选择.

..or is my only option to Change the Default to none from null

推荐答案

UPDATE TableName SET column = IFNULL(column, 0) + 1 WHERE ...

有关IFNULL的详细信息.如果不是NULL，它将返回第一个参数，否则返回第二个.

More info on IFNULL. It returns the first argument if it is not NULL, the second otherwise.

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