将数据从一个字段复制到每一行的另一字段 [英] Copy data from one field to another on every row

问题描述

所以我得到了:

id    number
 1      0
 2      0
 3      0

是否存在一条sql语句，用于将所有内容从id复制到数字?

Is there a sql statement to copy everything from id into number?

我要编写一个php scrip进行选择，然后更新每一行.我的SQL知识很基础，但是我敢肯定有一种聪明的方法可以做到这一点:

I'm about to write a php scrip to select, then update every row. My SQL knowledge is pretty basic, but I'm sure there's a smart guy way to to do this:

背景:ID过去一直是应用程序中显示的数字，并且是唯一的.该数字不再具有我要添加的一些新功能的唯一性，因此我需要将其移到不唯一的字段中，同时保持旧的完整性.

Background: The id used to be a number that was displayed in the app and was unique. That number is no longer unique with some new features I'm adding--so I need to move it to a field that isn't unique while maintaining the integrity of the old.

推荐答案

您可以使用update语句并引用这些列.只需执行以下操作:

You can use an update statement and reference the columns. Just do the following:

update mytable set number = id

在每一行上将数字设置为等于id.享受吧！

That sets number equal to id on each row. Enjoy!

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