Mysql query using where and group by clause

Question

I have the following table.

mysql> select * from consumer9;
+------------+--------------+-------------------+
| Service_ID | Service_Type | consumer_feedb         


        

Answer 1

Use the having clause instead of where

SELECT  Service_ID, Service_Type, SUM(consumer_feedback) 
FROM consumer9 
GROUP BY Service_ID 
HAVING Service_Type='Printer';

Regards.

Answer 2

The following query should work.

select Service_ID, Service_Type, sum(consumer_feedback) 
from consumer9 
where Service_Type=Printer
group by Service_ID, Service_Type;

Remember, the where clause goes before the group by clause and all non-aggregated terms in the select part will have to be present in the group by clause.