PostgreSQL/Store Procedure Function/Input Alias

Declare Input alias

postgres=# CREATE FUNCTION "triple_price" (double precision) RETURNS double precision AS "
postgres"#   DECLARE
postgres"#      -- Declare input_price as an alias for the
postgres"#      -- argument variable normally referenced with
postgres"#      -- the $1 identifier.
postgres"#     input_price ALIAS FOR $1;
postgres"#
postgres"#   BEGIN
postgres"#      -- Return the input price multiplied by three.
postgres"#     RETURN input_price * 3;
postgres"#   END;
postgres"#  " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=#
postgres=# select triple_price(100);
 triple_price
--------------
          300
(1 row)
postgres=#