PostgreSQL function that safely casts a string value to an integer. Useful when sorting string fields as numbers :)

safe_cast_str_to_int.sql

-- Function: "Safe_Cast_Str_to_Int"(character varying, integer)

CREATE OR REPLACE FUNCTION "Safe_Cast_Str_to_Int"(input_string character varying, default_value integer DEFAULT NULL::integer)
  RETURNS integer AS
$BODY$
BEGIN
	BEGIN
		RETURN input_string::integer;
	EXCEPTION WHEN data_exception THEN
		RETURN default_value;
	END;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION "Safe_Cast_Str_to_Int"(character varying, integer) OWNER TO postgres;