ISNULL vs COALESCE

ISNULL & COALESCE with some common features makes them equivalent, but some features makes them work and behave differently, shown below.- Similarity:Both can be use to build/create a CSV list as shown below: USE [AdventureWorks] GO DECLARE @csv VARCHAR(2000) SELECT @csv = ISNULL(@csv + ‘, ‘, ”) + FirstName FROM Person.Contact WHERE ContactID <= 10…