concat two integers and result as string in SQL

You can CAST your integer field to varchar and then concatenate them as you want.

DECLARE @ID INT 
DECLARE @Number INT 

SET @ID = 101 
SET @Number = 9  

SELECT CAST(@ID AS VARCHAR(10) ) +'.'+ CAST(@Number AS VARCHAR(10) ) 

In SQL 2012 (and later) I now find this easier using CONCAT (better performance too)

SELECT CONCAT(@ID, '.', @Number) 

any NULL elements are converted to empty-strings preventing NULL propagation, which saves having to do the even more complex:

SELECT ISNULL(CAST(@ID AS VARCHAR(10) ), '') +'.'+ ISNULL(CAST(@Number AS VARCHAR(10) ) , '')