如何将字符串附加到 MySQL 中的现有字段？

How can I append a string to an existing field in MySQL?

提问by Matt Elhotiby

I want to update the code on all my record to what they currently are plus _standard any ideas?

我想将我所有记录上的代码更新为它们当前的代码以及 _standard 有什么想法吗？

So for example if the codes are apple_1 and apple_2 I need them to be apple_1_standard and apple_2_standard

例如，如果代码是 apple_1 和 apple_2，我需要它们是 apple_1_standard 和 apple_2_standard

Before:

前：

id   code
------------
1    apple_1 
1    apple_2

Psuedo Query:

伪查询：

update categories set code = code + "_standard" where id = 1;

Expected result:

预期结果：

id   code
----------------------
1    apple_1_standard 
1    apple_2_standard

回答by Daniel Vassallo

You need to use the CONCAT()function in MySQL for string concatenation:

您需要使用CONCAT()MySQL 中的函数进行字符串连接：

UPDATE categories SET code = CONCAT(code, '_standard') WHERE id = 1;

回答by gus

Update image field to add full URL, ignoring null fields:

更新图像字段以添加完整 URL，忽略空字段：

UPDATE test SET image = CONCAT('https://my-site.com/images/',image) WHERE image IS NOT NULL;