`CREATE FUNCTION`

Create a new function.

Table of contents

Synopsis

CREATE [OR REPLACE] FUNCTION function_name
    ( [ [arg_name] arg_type ] [, ...] ] )
RETURNS return_type
LANGUAGE language_name
AS 'definition'

CREATE FUNCTION creates a new user-defined function.

CREATE OR REPLACE FUNCTION will either create a new function, or replace an existing function.

The signature of the function is defined by its schema, name, and input arguments.

You can overload functions by defining two functions of the same name, but with a different set of input arguments.

function_name

The name of the function to create.

arg_name

The optional name given to an argument. Function arguments do not retain names, but you can name them in your query for documentation purposes.

arg_type

The data type of a given argument.

return_type

The returned data type of the function. The return type can be any supported type.

language_name

The registered language which should be used for the function.

definition

A string defining the body of the function.