这是我的查询
SELECT
COUNT(C.SETID)
FROM
MYCUSTOMER C
LEFT OUTER JOIN MYCUSTOPTION CO
ON
(C.SETID = CO.SETID
AND C.CUST_ID = CO.CUST_ID
AND CO.effdt = (
SELECT MAX(COI.EFFDT)
FROM MYCUSTOPTION COI
WHERE
COI.SETID = CO.SETID
AND COI.CUST_ID = CO.CUST_ID
AND COI.EFFDT <=SYSDATE
)
)
这里是我正在收到的错误信息..
我究竟做错了什么？？？
您可以通过推动子查询来重写它,使其不外部连接：
select Count(C.setid)
from mycustomer C
left outer join (select *
from mycustoption co
where co.effdt <= (select Max(COI.effdt)
from mycustoption COI
where COI.setid = co.setid
and COI.cust_id = co.cust_id
and COI.effdt <= sysdate)) co
on ( C.setid = CO.setid
and C.cust_id = CO.cust_id )
