Er is een query fout opgetreden:
select gr.id groepid,min(trplan.startdate) start from op_training_group gr, op_training_construct trplan where gr.training = and gr.id = trplan.groupid group by gr.id order by start
1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'and gr.id = trplan.groupid group by gr.id order by start' at line 5