Merge column value based on another column value - TSQL - sql

Question

I m using the below query to merge column Message based on column 'Customer_Name' from table Customers
SELECT
[Customer_Name],
STUFF((SELECT
', ' + LTRIM(RTRIM([Message]))
FROM [dbo].[Customers] t2
WHERE t2.[Customer_Name] = t1.[Customer_Name]
FOR XML PATH ('')), 1, 1, '')
FROM [dbo].[Customers] t1
GROUP BY [Customer_Name]
Using the above code, the Message are separated by , but i want a new line. i try to use CHAR(13)+CHAR(10) but i getting #x0D; and the merge column seems to be wrong.
Any idea on how to fix it will greatly appreciate.
Answer using #Larnu help and posts on comments
SELECT
[Customer_Name],
STUFF((SELECT
(CHAR(13) + CHAR(10)) + LTRIM(RTRIM([Message]))
FROM [Customers] t2
WHERE t2.[Customer_Name] = t1.[Customer_Name]
FOR XML PATH (''),TYPE
).value('(./text())[1]','varchar(MAX)'),1,2,'')
FROM [Customers] t1
GROUP BY [Customer_Name]

Answer 1

Your solution use xml serialization .
#x0D; is xml serialization of char(13)
If you use at least SQL Server 2017 you can use STRING_AGG function
SELECT
[Customer_Name],
STRING_AGG([Message],', ') as [Messages]
FROM [dbo].[Customers] t1
GROUP BY [Customer_Name]
otherwise you can add replace.
SELECT
[Customer_Name],
REPLACE(
STUFF((SELECT
', ' + LTRIM(RTRIM([Message]))
FROM [dbo].[Customers] t2
WHERE t2.[Customer_Name] = t1.[Customer_Name]
FOR XML PATH ('')), 1, 2, ''),
'#x0D;',
CHAR(13)) as [Messages]
FROM [dbo].[Customers] t1
GROUP BY [Customer_Name]

Answer 2

The correct method to prevent XML entitization is actually to generate it as the xml data type using the TYPE option, then pull it back out with .value
DECLARE #sep NVARCHAR(10) = ', '; -- or you can use CHAR(13)+CHAR(10)
SELECT
[Customer_Name],
STUFF(
(SELECT #sep + LTRIM(RTRIM([Message]))
FROM [dbo].[Customers] t2
WHERE t2.[Customer_Name] = t1.[Customer_Name]
FOR XML PATH (''), TYPE
).value('text()[1]','nvarchar(max)'), 1, LEN(#sep), '')
FROM [dbo].[Customers] t1
GROUP BY [Customer_Name]