The COALESCE function can be used in Oracle/PLSQL.
You could use the coalesce function in a SQL statement as follows:
SELECT COALESCE( address1, address2, address3 ) result FROM suppliers;
The above COALESCE function is equivalent to the following IF-THEN-ELSE statement:
IF address1 is not null THEN result := address1; ELSIF address2 is not null THEN result := address2; ELSIF address3 is not null THEN result := address3; ELSE result := null; END IF;
The COALESCE function will compare each value, one by one.