存储过程，函数或游标mysql将多行合并为一行，而无需使用group_concat

Question

I have a problem in production database. Currently, I have task like this below image.

Before

After

I have done this task using group_concat . But, I can use this method/function since string or character have limit in 1024 . I can change this even administrator or someone. Because application will down temporary. This is too risk in production.

So, I'm gonna ask if someone have idea or ever create stored procedure, function, or cursor like group_concat .

Thanks all

Answer 1

The setting is connection-based and a dynamic variable. Increase it to 200000 below, for instance.

SET SESSION group_concat_max_len = 200000;
SELECT @@group_concat_max_len;
+------------------------+
| @@group_concat_max_len |
+------------------------+
|                 200000 |
+------------------------+

See the manual page for group_concat_max_len .