Simple Scalar SQL UDFs

Syntax

create_function_statement ::=
        CREATE [ OR REPLACE ] FUNCTION function_name (argument_list)
        RETURNS return_type
         AS $$
         { function_body }
         $$ LANGUAGE SQL
         ;

 function_name ::= identifier
 argument_list :: = { value_name type_name [, ...] }
 value_name ::= identifier
 return_type ::= type_name
 function_body ::= A valid SQL statement

Usage Notes

The following usage notes apply when using simple scalar SQL UDF’s:

• During this stage, the SQL embedded in the function body must be of the type SELECT expr;. Creating a UDF with invalid SQL, or with valid SQL of any other type, results in an error.

• The argument list can be left empty.

• SQL UDFs can reference other UDF’s.

NOTICE: A function cannot (directly or indirectly) reference itself (such as by referencing another function that references it).

Restriction

Simple scalar SQL UDF’s cannot currently reference other UDF’s.