I am using GROUP_CONCAT in my query to collect some IDs. Imagine I have two columns as follow:
user_id
item
The code looks like this:
SELECT user_id, GROUP_CONCAT(item) AS all_items_by_user
FROM table
GROUP BY user_id
However, I noticed that the all_items_by_user
column can accommodate up to a certain number of characters in each cell. This limit is around 1100 in my case, whereas I expect at least 10 times more. I wondered whether there is any way to increase this limit? Thank you.
This is controlled by group_concat_max_len
, a system variable.
The documentation describes how to change the value and what it really means.
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