René Nyffenegger's collection of things on the web
René Nyffenegger on Oracle - Most wanted - Feedback
 

concat [Oracle SQL]

concat('string1', 'string2')

select concat(concat('Hello', ' '), 'World') from dual;

Hello World

The concatenation operator

The concatenation operator is a short hand form for concat and consists of two vertical bars: 
select 'Hello' || ' ' || 'World' from dual;

Hello World