Coalesce in SQL | How to use coalesce funtion in SQL.

COALESCE Function SQL

The SQL coalesce function will gives the first non-null string.

Syntax: coalesce (strng1, string2, string3 … stringn)
Ex:

select coalesce('a','b','c'), coalesce(null,'a',null,'b') from dual;

coalesce('a','b','c')
----------------------
a

 coalesce(null,'a',null,'b')
--------------------------
a

output on tool

Works in:	SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse