SQL - SUM within subquery - sql

Question

I have the following code that looks at the SalesVol of different products and groups it by transaction_week
SELECT a.transaction_week,
SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
WHERE series in (62,236,501,52)
GROUP BY a.transaction_week
ORDER BY a.transaction_week
| tw | SalesVol |
| 1 | 4768 |
| 2 | 4567 |
| 3 | 4354 |
| 4 | 4678 |
I want to be able to have multiple subqueries where I change the series numbers for example.
SELECT a.transaction_week,
(SELECT SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
WHERE series in (62,236,501,52)) as personal care
(SELECT SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
WHERE series in (37,202,203,456)) as white goods
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
GROUP BY a.transaction_week
ORDER BY a.transaction_week
I can't get the subqueries at work as it is giving me the overall sum value and not grouping it by transaction_week

Answer 1

Instead of using subqueries, add series to the condition of the CASE statements:
SELECT a.transaction_week,
sum(CASE WHEN series IN (62,236,501,52) AND record_type IN (6,37,13)
THEN quantity ELSE 0 END) as personal_care,
sum(CASE WHEN series IN (37,202,203,456) AND record_type IN (6,37,13)
THEN quantity ELSE 0 END) as white_goods
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
GROUP BY a.transaction_week
ORDER BY a.transaction_week;

Answer 2

You just miss the a.transaction_week in you subquery. The JOIN in outer query is unneccessary.
SELECT a.transaction_week,
(
SELECT SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a2
LEFT JOIN table 2 b ON b.Date = a2.transaction_date
LEFT JOIN table 3 c ON c.sku = a2.product
WHERE series in (62,236,501,52) AND a2.transaction_week = a.transaction_week
) as personal care,
(
SELECT SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a 2
LEFT JOIN table 2 b ON b.Date = a2.transaction_date
LEFT JOIN table 3 c ON c.sku = a2.product
WHERE series in (37,202,203,456) AND a2.transaction_week = a.transaction_week
) as white goods
FROM table 1 a
GROUP BY a.transaction_week
ORDER BY a.transaction_week

Answer 3

Try this it would work fast as well as up to your requirement:
SELECT a.transaction_week ,
whitegoods.SalesVol AS 'White Goods' ,
personalcare.SalesVol1 AS 'Personal Care'
FROM table1 a
LEFT JOIN table2 b ON b.[Date] = a.transaction_date
LEFT JOIN table3 c ON c.sku = a.product
CROSS APPLY ( SELECT SUM(CASE WHEN record_type IN ( 6, 37, 13 )
THEN quantity
ELSE 0
END) AS SalesVol
FROM table1 a2
WHERE b.[Date] = a2.transaction_date
AND c.sku = a2.product
AND series IN ( 37, 202, 203, 456 )
AND a2.transaction_week = a.transaction_week
) whitegoods
CROSS APPLY ( SELECT SUM(CASE WHEN record_type IN ( 6, 37, 13 )
THEN quantity
ELSE 0
END) AS SalesVol1
FROM table1 a2
WHERE b.[Date] = a2.transaction_date
AND c.sku = a2.product
AND series IN ( 62, 236, 501, 52 )
AND a2.transaction_week = a.transaction_week
) personalcare
GROUP BY a.transaction_week
ORDER BY a.transaction_week

Answer 4

You should use the UNION operator. Please refer to the query below:
select a.transaction_week, SalesVol from
(SELECT a.transaction_week as transaction_week,
SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
WHERE series in (62,236,501,52)
UNION
SELECT a.transaction_week as transaction_week,
SUM(CASE WHEN record_type IN (6,37,13) THEN quantity ELSE 0 END) as SalesVol
FROM table 1 a
LEFT JOIN table 2 b ON b.Date = a.transaction_date
LEFT JOIN table 3 c ON c.sku = a.product
WHERE series in (37,202,203,456)
) AS tbl1
GROUP BY tbl1.transaction_week
ORDER BY tbl1.transaction_week