Перенести хранимую функцию с mysql в postgresql

CREATE DEFINER = ' bhc_db'@'%' FUNCTION `fCreateProcessID`(

prefix CHAR (3)

)

RETURNS varchar (18) CHARSET utf8

NOT DETERMINISTIC

CONTAINS SQL

SQL SECURITY DEFINER

COMMENT ''

BEGIN

DECLARE newpid VARCHAR (18);

DECLARE yy, mm, dd CHAR (2);

DECLARE id_part CHAR (7);

DECLARE curr_max INT DEFAULT 0;





SET yy = SUBSTR (CAST (YEAR (CURRENT_DATE) AS CHAR (4)),3,2);

SET mm =

IF (MONTH (CURRENT_DATE)