Example

Define a scalar function that returns the tangent of a value using the existing SIN and COS built-in functions.

         CREATE FUNCTION TAN
              (X DOUBLE)
           RETURNS DOUBLE
           LANGUAGE SQL
           CONTAINS SQL
           NO EXTERNAL ACTION
           DETERMINISTIC
           RETURN SIN(X)/COS(X)

Notice that a parameter name (X) is specified for the input parameter to function TAN. The parameter name is used within the body of the function to refer to the input parameter. The invocations of the SIN and COS functions, within the body of the TAN user-defined function, pass the parameter X as input.