Scalar Python UDF example

The following example creates a function that compares two numbers and returns the larger value. Note that the indentation of the code between the double dollar signs ($$) is a Python requirement. For more information, see CREATE FUNCTION.

create function f_py_greater (a float, b float)
  returns float
stable
as $$
  if a > b:
    return a
  return b
$$ language plpythonu;

The following query calls the new f_greater function to query the SALES table and return either COMMISSION or 20 percent of PRICEPAID, whichever is greater.

select f_py_greater (commission, pricepaid*0.20) from sales;