When a view is using GROUP_CONCAT function, the value is truncated in MySQL.
Mysql truncates to the maximum length that is given by the group_concat_max_len system variable, which is a default value of 1024 bytes.
For more information, refer to MySQL Documentation - GROUP_CONCAT(expr).
To resolve this issue, use one of the following options:
For only self-managed installations, change the value of group_concat_max_len at runtime by doing the following (val is an unsigned integer):
SET [GLOBAL | SESSION] group_concat_max_len = val;
For both self-managed installations and cloud sites, modify the SQL for the view using a combination of CONCATand GROUP_CONCAT.
SELECT GROUP_CONCAT(last_name) FROM employee
SELECT SUBSTRING( CONCAT( GROUP_CONCAT( IF(employee_id BETWEEN 1 AND 100, CONCAT(',', last_name), '') SEPARATOR '' ), GROUP_CONCAT( IF(employee_id BETWEEN 101 AND 200, CONCAT(',', last_name), '') SEPARATOR '' ) ), 2 ) AS result FROM employee
This article applies to all versions of Appian.
Last Reviewed: April 2016
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