This blog shows how to get the First Non Null Value from a list of expression using COALESCE function in SQL
Example:
DECLARE @Val1 int
DECLARE @Val2 int
DECLARE @Val3 int
SET @Val2 = 101
SET @Val3 = 102
SELECT COALESCE(@Val1 , @Val2 , @Val3 )
The expected result would be 101