How to use group by in SQL Server query?

Question

I have problem with group by in SQL Server

I have this simple SQL statement:

select * 
from Factors 
group by moshtari_ID

and I get

Answer 1

You need to apply aggregate function such as max(), avg() , count() in group by.

For example this query will sum totalAmount for all moshtari_ID

select moshtari_ID,sum (totalAmount) from Factors group by moshtari_ID;

output will be

moshtari_ID    SUM
2              120000 
1              200000