Using the SQL Coalesce function in SQL Server

Pragmatic Guide to SQL Server COALESCE Expression coalesce When using COALESCE with empty strings, keep in mind that an empty string is treated as a non-NULL value This means that if an empty string is coalesce Coalesce returns the first non-null value in a list If all the values in the list are NULL, then the function returns null

coalesce The Coalesce function returns the value of the first argument that is not Null This function is often applied to one or more columns of data to check for