Automatically generate columns name in CTE using SQL Server - sql-server

Question

I am building a pivot query inside a CTE. I have a table Table_1:
Store Week xCount
------- ---- ------
101 1 138
105 1 37
109 1 59
101 2 282
109 2 97
105 3 60
109 3 87
This is the query I used to pivot Table_1:
with CTE as
(
select
*
from
(select
store, week, xCount
from
table_1) src
pivot
(sum(xcount)
for week in ([1], [2], [3])
) piv;
)
Select *
From CTE
And this is the result I got:
| STORE | 1 | 2 | 3 |
+-------+-----+-----+-----+
| 101 | 138 | 282 | null|
| 105 | 37 | null| 60 |
| 109 | 59 | 97 | 87 |
The result is fine, but now there is one more WEEK added.
I want to develop a CTE with pivot query that will automatically generate distinct weeks and create a column on that basis.
I did some research and found a recursive CTE can be used to do this. I am new to recursive CTE, so please anyone can help me to solve this issue.
I also tried dynamic pivot query but CTE does not allow dynamic query.
Please help.

Answer 1

dynamic pivot doesn't work inside CTE
No, but a CTE works inside a dynamic query:
{assuming you have declared the variables used below}
SELECT #Cols = {query to get the column names in a comma-separated string}
SET #sql='
with CTE as
(
select
*
from
(select
store, week, xCount
from
table_1) src
pivot
(sum(xcount)
for week in ('+#Cols+')
) piv;
)
Select *
From CTE
'
EXEC (#sql)
Can i use recursive CTE?
No this isn't an appropriate use-case for a recursive CTE.

Answer 2

/* Variable to hold unique Week to be used in PIVOT clause */
DECLARE #Weeks NVARCHAR(MAX) = N''
/* Extract unique Week names with pivot formattings */
SELECT #Weeks = #Weeks + ', [' + COALESCE(week, '') + ']'
FROM (SELECT DISTINCT week FROM table_1) DT
/* Remove first comma and space */
SELECT #Weeks = LTRIM(STUFF(#Weeks , 1, 1, ''))
/* Variable to hold t-sql query */
DECLARE #CTEStatement NVARCHAR(MAX) = N''
/* Generate dynamic PIVOT query here */
SET #CTEStatement=N'
;WITH CTE as
( SELECT *
FROM
(SELECT
store
,week
,xCount
FROM
table_1) SRC
PIVOT
(SUM(xcount)
FOR week in ('+ #Weeks +')
) PIV;
)
SELECT *
FROM CTE
'
EXEC (#CTEStatement)