Netezza中的子查询

我正在尝试将SQL 11从Oracle 11 G移植到Netezza.

这是我在Oracle中的查询:

SELECT
    ID, TEACHERID, CLASS, SECTION, MAJOR, SUPERVISOR, COURSE, SCORE, SCOREDATE, 
    (select SCORE from STUDENT_SCORES d2 where d2.ID=d1.ID and d2.SCOREDATE (d1.SCOREDATE)-28 and d1.COURSE=d2.COURSE)  as PRIORSCORE, 
    (d1.SCOREDATE)-28 as PRIORSCOREDT,
    REMCD
FROM 
    STUDENT_SCORES d1
WHERE 
    TEACHERID='T1' AND SCOREDATE=(SELECT MAX(SCOREDATE) FROM STUDENT_SCORES WHERE TEACHERID='T1')

当我在Netezza中运行它时出现错误:

ERROR:  (2) This form of correlated query is not supported - consider rewriting

如何为Netezza重写此查询？请帮忙.