Question

I have a SQL squery,

SELECT * FROM gr_person as GR
INNER JOIN ADDRESS ON GR.address_code = ADDRESS.address_code 
JOIN dbo.GR_PERSON_TYPES GPT
ON GR.person_type = GPT.person_type 
WHERE event_number = '101000008' 
ORDER BY GPT.type_key

That returns

GR.event_number, GR.person_type, GR.customer_code, GPT.type_key, GPT.event_type, GPT.person_type
101000008          Wife           10001             3             2                 Wife
101000008          Wife           10001             4             3                 Wife

I want this query to return only ONE ROW if the GR.PERSON_TYPE is SAME as in this case.

I tried adding a group by GR.PERSON_TYPE, but can’t help it.

Can somebody tell me how to do it?

Answer 1

You can group by person_type to get one result for the group Wife, but you will need to aggregate or exclude your other columns.

For instance, if you only want one record for Wife, what should the value for type_key and event_type be? If you want to see the maximum or average event_type for your Wife group, you could use max(event_type) or avg(event_type). The documentation for your DBMS should be able to explain all the aggregate functions for you.