Last week, when using the
GROUP_CONCAT() function on a MySQL database, I got an unexpected result.
Indeed, instead of getting my result as
VARCHAR types, I got it as
BLOB types! For information, a
BLOB is a binary large object that can hold a variable amount of data:
BLOB values are treated as binary strings, it is not easy to use. This is why we would prefer to have
So the question is how to get around this frustrating problem?
The answer is, for once, very simple!
You simply need to:
- Open your my.ini or my.cnf file;
- Change the value of the
group_concat_max_lensystem variable to 512 (no ‘k’ suffix);
- Restart the mysql service
To verify if the value has been successfully updated, execute the following command in your mysql client:
Note that you cannot set the value of
group_concat_max_len to less than 1Kb using the MySQL Administrator GUI. Which means that the only way to set this system variable to 512 (which is less than 1Kb) is to edit your MySQL configuration file as described above.