SQLSTATE[42000]: Syntax error or access violation: 1140 Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause code example

Example: SQLSTATE[42000]: Syntax error or access violation: 1140 Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause

#database.php

'strict' => false after that you can use group by on a single column too.