SQL Server 2017 has its own STRING_SPLIT function, so no need to write your own.

declare @r nvarchar(max) = ''
declare @i int = 0
declare...

I find YYYY-MM-DD a bit more readable than YYYYMMDD.
I once switched my SQL queries to YYYYMMDD from YYYY-MM-DD as there was a problem with the ISO 8601 dashed standard in...

You can use set identity_insert table_name on
e.g:
set identity_insert [dbo].[tblOrderNumberLog] ON
INSERT INTO [dbo].[tblOrderNumberLog](ID)
 select row_number() over (order by (select null))
from sys.columns
set identity_insert [dbo].[tblOrderNumberLog] OFF

1. CROSS APPLY needs a space between CROSS and APPLY
2. 'or' is not a valid alias to use for a table (without square brackets) as it is a reserved...

Does this give you what you want?:
SELECT COUNT(B.A_ID) AS TEL, ID, A_TEXT, A_ID FROM A FULL OUTER JOIN B ON ID = A_ID GROUP BY ID, A_TEXT,...

LOL, Sorry I didn't notice the original post was that old. Someone else brought it back from the dead.

CROSS APPLY is a row level operator. So your table_valued_function will be run once for each row the rest of the query returns.
So my guess is that the query: