An IF - ELIF - ELSE structure

CREATE FUNCTION str_compare( str1 CHAR(20), str2 CHAR(20))
   RETURNING INTEGER;

   DEFINE result INTEGER;

   IF str1 > str2 THEN
      LET result = 1;
   ELIF str2 > str1 THEN
      LET result = -1;
   ELSE
      LET result = 0;
   END IF
   RETURN result;
END FUNCTION;

CREATE TABLE manager
(
   mgr_name   VARCHAR(30),
   department VARCHAR(12),
   dept_no    SMALLINT,
   direct_reports SET( VARCHAR(30) NOT NULL ),
   projects LIST( ROW ( pro_name VARCHAR(15),
   pro_members SET( VARCHAR(20) NOT NULL ) )
                    NOT NULL),
   salary     INTEGER,
);

CREATE FUNCTION checklist( d SMALLINT )
   RETURNING VARCHAR(30), VARCHAR(12), INTEGER;

   DEFINE name VARCHAR(30);
   DEFINE dept VARCHAR(12);
   DEFINE num INTEGER;

   SELECT mgr_name, department,
          CARDINALITY(direct_reports) 
      FROM manager INTO name, dept, num
      WHERE dept_no = d;
   IF num > 20 THEN
      EXECUTE FUNCTION add_mgr(dept);
   ELIF num = 0 THEN
      EXECUTE FUNCTION del_mgr(dept);
   ELSE
      RETURN name, dept, num;
   END IF;

END FUNCTION;