Encounter a problem with your group_concat process, the record here what: there are in MySQL configuration parameters group_concat_max_len, it will limit the use of the maximum string length group_concat returned, the default is 1024.
Query group_concat_max_len Size:
show variables like 'group_concat_max_len';
Modify group_concat_max_len Size:
method one:
SET GLOBAL group_concat_max_len = 1024 * 10;
SET SESSION group_concat_max_len = 1024 * 10;
This method may be used without rebooting the server, but the server after restarting the restore configuration. You can solve this problem by modifying MySQL (my.ini) configuration file.
Method Two:
Modify MySQL (my.ini) configuration file, you need to restart the server to take effect.
Find my.ini file, modify or add if:
group_concat_max_len = 10240
Restart to take effect.