SQL query to find Date, TranscationAmount_US,TransactionAmount_UK - sql

Question

We have 2 tables:
Transaction (AccountId,Date,TransactionAmount)
Master(Aid,Country)
We need to find Date, TotalTAmt_US, Total_TAmt_UK
My solution:
Select
Date,
CASE WHEN Country in ('US') THEN SUM(TransAmt) ELSE '0'END AS TotalTAmt_US,
CASE WHEN Country in ('UK') THEN SUM(TransAmt) ELSE '0'END AS TotalTAmt_UK
FROM
(
SELECT
T.Date As Date,
M.Country As Country,
SUM(T.TransAmt) As TransAmt,
FROM
Transaction T JOIN Master M On T.Aid = M.Aid
WHERE Country in ('US','UK')
group by Date,Country
) As T1
group by Date;
Is this right?
Can we use Country in CASE WHEN without pulling it as I do not want to pull it and then group by it.
Advice please.
Thanks.

Answer 1

You have to declare in GROUP BY section all columns that you use in select statement.
So just put your cases to the grouping.
Select
Date,
CASE WHEN Country in ('US') THEN TransAmt ELSE 0 END AS TotalTAmt_US,
CASE WHEN Country in ('UK') THEN TransAmt ELSE 0 END AS TotalTAmt_UK
FROM
(
SELECT
T.Date As Date,
M.Country As Country,
SUM(T.TransAmt) As TransAmt,
FROM
Transaction T JOIN Master M On T.Aid = M.Aid
WHERE Country in ('US','UK')
GROUP BY Date,Country
) As T1
GROUP BY Date, CASE WHEN Country in ('US') THEN TransAmt ELSE 0 END AS
TotalTAmt_US, CASE WHEN Country in ('UK') THEN TransAmt ELSE 0 END
AS TotalTAmt_UK
Additionaly, remove the SUM() function in your case conditions. If you put them to the GROUP BY you can get error:
ORA-00934: Group function is not allowed here.
And, in the end, remove the ticks in zeros in ELSE conditions. You can get another error about incosistens data types.

Answer 2

I believe you wanted to do a conditional aggregation getting the sum for all US based transaction for a day and the sum of all the UK based transactions for the same day. Then you had to move the CASE into the sum(), adding the amount only if the country is the one you look for, otherwise zero.
Also your subquery isn't necessary.
SELECT t.date,
sum(CASE m.country
WHEN 'US' THEN
t.transamt
ELSE
0
END) totaltamt_us,
sum(CASE m.country
WHEN 'UK' THEN
t.transamt
ELSE
0
END) totaltamt_uk
FROM transaction t
INNER JOIN master m
ON m.aid = t.accountid
WHERE m.county IN ('US',
'UK')
GROUP BY t.date;
If you don't insist on having the different sums in different columns, but would also accept rows, it can be as simple as:
SELECT m.country,
t.date,
sum(t.transamt) totaltamt
FROM transaction t
INNER JOIN master m
ON m.aid = t.accountid
WHERE m.county IN ('US',
'UK')
GROUP BY m.country,
t.date;

Answer 3

I think you want conditional aggregation:
SELECT Date,
SUM(CASE WHEN Country in ('US') THEN TransAmt ELSE 0 END) AS TotalTAmt_US,
SUM(CASE WHEN Country in ('UK') THEN TransAmt ELSE 0 END) AS TotalTAmt_UK
FROM Transaction T JOIN
Master M
On T.Aid = M.Aid
WHERE Country in ('US', 'UK')
GROUP BY Date;
Notes:
You do not need two levels of aggregation.
Numbers should not be enclosed in single quotes, so 0, not '0'.