I have the following query:
SELECT cust_id,cust_name,SUM(calls.duration) as duration
FROM
calls, telephone
WHERE calls.from_t_no = telephone.t_no
AND
calls.duration <=60
group by telephone.cust_id, telephone.cust_name
Which give the following results;
cust_id cust_name duration
0123456789 Avi 18
1234567890 Benny 27
2345678901 Gadi 13
3456789012 Dalia 69
4567890123 Hilla 5
5678901234 Varda 14
7890123456 Haim 20
8901234567 Tali 20
9012345678 Yoram 46
I also have this query:
SELECT cust_id,cust_name,SUM(calls.duration) as duration
FROM calls ,telephone
WHERE to_t_no = telephone.t_no
AND
calls.duration >=50开发者_Go百科0
group by telephone.cust_id, telephone.cust_name
Which provides the following results:
cust_id cust_name duration
2345678901 Gadi 50022
4567890123 Hilla 50000
the second query is actually another filter or condition which the first query should match. I cannot include the second query within the first query because it uses different columns. I need to "subtract" the second query from the first query.
How do I do that?
If you truly can't merge the queries, you can JOIN the results like this:
SELECT T0.cust_id, T0.cust_name, T0.duration FROM
( SELECT cust_id,cust_name,SUM(calls.duration) as duration
FROM
calls, telephone
WHERE calls.from_t_no = telephone.t_no
AND
calls.duration <=60
group by telephone.cust_id, telephone.cust_name) T0
JOIN
(SELECT cust_id,cust_name,SUM(calls.duration) as duration
FROM calls ,telephone
WHERE to_t_no = telephone.t_no
AND
calls.duration >=500
group by telephone.cust_id, telephone.cust_name) T1
ON T0.cust_id = T1.cust_id
Try to post the complete structure of your table and describe what you really need.
If i understand correctly the problem the conditions that you are exposing are mutually exclusive. I think that there is not possible that any record match both conditions because the final query will look like this:
SELECT cust_id,cust_name,SUM(calls.duration) as duration
FROM calls ,telephone
WHERE
to_t_no = telephone.t_no
AND calls.from_t_no = telephone.t_no
AND calls.duration <=60
AND calls.duration >=500
group by telephone.cust_id, telephone.cust_name;
If what you want is a general solution to make a "query over a query" you can use this kind of sentence:
SELECT field1, field2 FROM
(SELECT field1, field2, ..., fieldn FROM table WHERE condition) AS filteredTable
WHERE anyCondition;
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