SQL Pivot Query with aggregation & Total - sql

Question

Table-A
ProductId
BrandName
1
Brand-1
2
Brand-2
3
Brand-3
Table-B
DCDate
DCNo
ProductId
Weight
2021-03-09
3
1
12.5
2021-03-09
3
1
12.6
2021-03-09
3
1
12.5
2021-03-09
3
2
10.5
2021-03-09
3
2
10.4
2021-03-09
3
3
15.5
2021-03-09
1
1
12.5
2021-03-09
1
3
15.7
2021-03-09
2
2
10.6
2021-03-09
4
1
12.7
2021-03-09
4
1
12.6
Expected Result:-
BrandName
1
2
3
4
Brand-1
1
0
3
2
Brand-2
0
1
2
0
Brand-3
1
0
1
0
Need Dynamic Pivot Query
What i tried
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT ',' + QUOTENAME([DCNo]) from [Table-B] FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)') ,1,1,'')
set #query = 'SELECT ' + #cols + '
from
(
SELECT a.[DCNo] , b.[BrandName], count(*) as Total FROM [Table-B] a inner join [Table-A] b on a.[ProductID]=b.[ProductID] group by [DCNo] , b.[BrandName] order by DCNo, b.[BrandName]
) x
pivot
(
max(Total)
for DCNo in (' + #cols + ')
) p '
execute(#query)

Answer 1

I've recreated it in a sqlfiddle: http://sqlfiddle.com/#!18/d1554/9 .
You were close but I sometimes find it easier to move all sum/count/grouping logic to the PIVOT section of the query instead. Results in simpler queries (most of the times)
CREATE TABLE [Table-A] (
ProductId INT,
BrandName VARCHAR(50)
)
CREATE TABLE [Table-B](
DCDate DATETIME,
DCNo INT,
ProductId INT,
Weight DECIMAL
)
INSERT INTO [Table-A] VALUES
(1, 'CAT'),
(2, 'APPLE'),
(3, 'PARROT')
INSERT INTO [Table-B] VALUES
('2021-03-09', 3, 1, 12.5),
('2021-03-09', 3, 1, 12.6),
('2021-03-09', 3, 1, 12.5),
('2021-03-09', 3, 2, 10.5),
('2021-03-09', 3, 2, 10.4),
('2021-03-09', 3, 3, 15.5),
('2021-03-09', 1, 1, 12.5),
('2021-03-09', 1, 3, 15.7),
('2021-03-09', 2, 2, 10.6),
('2021-03-09', 4, 1, 12.7),
('2021-03-09', 4, 1, 12.6)
-- Query
DECLARE #cols AS NVARCHAR(MAX) = '';
DECLARE #nullcols AS NVARCHAR(MAX) = '';
DECLARE #query AS NVARCHAR(MAX);
-- Determine columns
;WITH cte AS (
SELECT
DISTINCT
dcno,
',' + QUOTENAME([DCNo]) AS col,
', ISNULL(' + QUOTENAME([DCNo]) + ', 0) AS ' + QUOTENAME([DCNo]) AS nullcol
FROM [Table-B]
)
SELECT
#cols += col,
#nullcols += nullcol
FROM cte
ORDER BY dcno
SET #cols = SUBSTRING(#cols, 2, LEN(#cols))
-- create query
SET #query = N';with CTE AS
(
SELECT
a.BrandName,
a.ProductId,
b.DCNo,
1 as Value
FROM [Table-A] a
INNER JOIN [Table-B] b
ON a.ProductId = b.ProductId
)
SELECT BrandName ' + #nullcols + ' FROM
(SELECT * FROM cte) p
PIVOT
(
SUM(Value)
FOR DCNo IN (' + #cols + ')
) AS pvt
ORDER BY pvt.ProductId
'
-- SELECT #query
execute(#query)