mysql - 我用SQL语句 更新 行的时候,发现全部 中文都被清空了,请问怎么解决?

Question

UPDATE shop SET desn2 = "" WHERE desn2 REGEXP "[(联通)(移动)(电信)]";

我用这句的时候,发现中文都被清空了,而一些只有数字或者英语组成的单元格却没有被清空,请问怎么办?

我试了试,只要使用了中括号,就会莫名其妙被匹配:
我觉得应该是他把中文,分解成了 编码 ,然后用编码去匹配的
你自己写个试试.

SELECT '大家好' REGEXP '[不存在]';

这个应该不存在,但是她就是存在了!

Answer 1

This is just my understanding. There is no guarantee as to whether it is correct or not.
This is the "[]" description of mysql regular:

[ ] matches any single character.

[123] defines a set of characters, meaning to match 1 or 2 or 3.

Then, the way I understand characters to be saved is ascii code, which makes it easier to understand why there is a concept of character sets.

SELECT ASCII('Hello everyone'),ASCII('does not exist')
==>
The data result is: 229 228

Then it’s easy to understand why: select 229 REGEXP '[228]'==>1

Answer 2

select * from shop WHERE desn2 REGEXP "[(China Unicom)(Mobile)(Telecom)]";

Execute it and see what data matches the output
It is best to send the results so that you can analyze them