How to display the accurate sum when using 2 inner joins? - sql

Question

I am trying to get the results:
Quote = 12345
Total Assets = 14
Total Ordered = 22
When I run the queries separately I get the correct results, but when I put the two queries together my results are off (this is because the tables b and c do not represent each other)
my table summaries are as follows:
Select a.Quote, SUM(b.Quantity) As 'Total Assets'
FROM a
INNER JOIN b ON b.aId = a.Id
GROUP By a.Quote
Result: 12345 : 14
Select a.Quote, SUM(c.Quantity) As 'Total Ordered'
FROM a
INNER JOIN c on c.aId = a.Id
GROUP By a.Quote
Result: 12345 : 22
However, when I put them together:
Select a.Quote, SUM(b.Quantity)As 'Total Assets',SUM(c.Quantity) As 'Total Ordered'
FROM a
INNER JOIN b on b.Aid = a.Id
INNER JOIN c on c.Aid = a.Id
GROUP BY a.Quote
Result 12345 : 56 : 308
I played with the group by but was never able to get the proper result. Any thoughts?
So far the solution I came up with is
With abc AS
(
Select a.Quote, SUM(b.Quantity) As 'Total Assets'
FROM a
INNER JOIN b ON b.aId = a.Id
GROUP By a.Quote
)
SELECT abc.* , SUM(c.Quantity) As ' Total Ordered'
FROM abc
INNER JOIN c ON c.aid = a.Id
GROUP BY (all in abc)
It doesn't seem like the best way to get the results though..

Answer 1

Maybe use Left JOIN. The INNER JOIN will repeat rows of b and c. Also, try to see the result of:
Select a.Quote, b.Quantity As 'Total Assets', c.Quantity As 'Total Ordered'
FROM a
INNER JOIN b on b.Aid = b.Id
INNER JOIN c on c.Aid = c.Id
GROUP BY a.Quote
And check if it's the right results that are computed. Then compare it against:
Select a.Quote, b.Quantity As 'Total Assets', c.Quantity As 'Total Ordered'
FROM a
LEFT JOIN b on b.Aid = b.Id
LEFT JOIN c on c.Aid = c.Id
GROUP BY a.Quote