In Oracle Library: all fields except aggregate function queried after select must be added after group by

Solution: put group by into the sub query or put all query fields after select into group by

Error: not group by   Expression

Instance: Select   sum(hwjz),rq from   JcChargeInfo where   1=1    group   by   rq order   by   jcchargecode desc

Reason:

1. When group by and order by are used together, order by should follow group by

2. The field of order by must be followed by group by

3. The fields selected in the select statement to be queried must appear in the group by clause