Count dynamic items - sql-server

Question

I have a dynamic data Eg:
Name Date Class
______________
John 15/06/2019 AB
John 14/06/2019 B
John 13/06/2019 C
Tom 14/06/2019 C
Tom 13/06/2019 D
I want the result:
Name ClassA ClassB ClassC ClassD ClassCount
_____________________
John 1 2 1 0 4
Tom 0 0 1 1 2
I try someway,but it's not work.
thks.

Answer 1

You need some dynamic SQL to execute to get your desired result. Check this following script.
Note: Considering class name A to Z
Check this Demo for more details.
DECLARE #ColumnList VARCHAR(MAX)
DECLARE #sqlCommand VARCHAR(MAX)
;WITH CTE(Class,Name,Date)
AS
(
SELECT A.Cl Class,B.Name,B.Date
FROM (
SELECT 'A' Cl UNION ALL SELECT 'B' UNION ALL SELECT 'C' UNION ALL SELECT 'D' UNION ALL SELECT 'E' UNION ALL
SELECT 'F' UNION ALL SELECT 'G' UNION ALL SELECT 'H' UNION ALL SELECT 'I' UNION ALL SELECT 'J' UNION ALL
SELECT 'K' UNION ALL SELECT 'L' UNION ALL SELECT 'M' UNION ALL SELECT 'N' UNION ALL SELECT 'O' UNION ALL
SELECT 'P' UNION ALL SELECT 'Q' UNION ALL SELECT 'R' UNION ALL SELECT 'S' UNION ALL SELECT 'T' UNION ALL
SELECT 'U' UNION ALL SELECT 'V' UNION ALL SELECT 'W' UNION ALL SELECT 'X' UNION ALL SELECT 'Y' UNION ALL SELECT 'Z'
)A
INNER JOIN <your_table> B
ON B.Class LIKE '%' + A.Cl + '%'
)
SELECT #ColumnList =
STUFF((SELECT DISTINCT ('],[' + A.Class)
FROM CTE A
--ORDER BY (A.Class)
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')+']'
FROM CTE
SET #sqlCommand=
N'
SELECT
Name,A ClassA, B ClassB,C ClassC,D ClassD,
A+B+C+D ClassCount
FROM
(
SELECT Name,'+SUBSTRING(#ColumnList,2,LEN(#ColumnList))+'
FROM
(
SELECT A.Cl Class,B.Name,B.Date
FROM (
SELECT ''A'' Cl UNION ALL SELECT ''B'' UNION ALL SELECT ''C'' UNION ALL SELECT ''D'' UNION ALL SELECT ''E'' UNION ALL
SELECT ''F'' UNION ALL SELECT ''G'' UNION ALL SELECT ''H'' UNION ALL SELECT ''I'' UNION ALL SELECT ''J'' UNION ALL
SELECT ''K'' UNION ALL SELECT ''L'' UNION ALL SELECT ''M'' UNION ALL SELECT ''N'' UNION ALL SELECT ''O'' UNION ALL
SELECT ''P'' UNION ALL SELECT ''Q'' UNION ALL SELECT ''R'' UNION ALL SELECT ''S'' UNION ALL SELECT ''T'' UNION ALL
SELECT ''U'' UNION ALL SELECT ''V'' UNION ALL SELECT ''W'' UNION ALL SELECT ''X'' UNION ALL SELECT ''Y'' UNION ALL SELECT ''Z''
)A
INNER JOIN <your_table> B
ON B.Class LIKE ''%'' + A.Cl + ''%''
)A
PIVOT(
COUNT(Date)
FOR Class IN('+SUBSTRING(#ColumnList,2,LEN(#ColumnList))+')
)PVT
)AA'
--PRINT #sqlCommand
EXEC (#sqlCommand)