帮忙看看这个查询的意思

两步走易懂点：
查询1：SELECT CNO, Avg(SCORE.DEGREE) AS DEGREE FROM SCORE GROUP BY CNO;
查询2：SELECT * FROM SCORE WHERE DEGREE<DLOOKUP("DEGREE","查询1","CNO='"& [CNO] &"'");


一步走：
SELECT SCORE.*
FROM SCORE INNER JOIN (SELECT CNO, Avg(SCORE.DEGREE) AS DEGREE FROM SCORE GROUP BY CNO)  AS 平均分 ON SCORE.CNO = 平均分.CNO
WHERE SCORE.DEGREE<平均分.DEGREE;
或
SELECT * FROM SCORE WHERE DEGREE<DLOOKUP("AVG(DEGREE)","SCORE","CNO='"& [CNO] &"'");