oracle多表查询，如果某个表没有数据，查询不到结果，该怎么解决呀？

Question

连接语句如下：
from user a,assinfo b,payable c,gov d
where a.accountno = b.account_no
and b.cert_no = c.addresscode
and d.warmyear = c.warmyear
and b.cert_no = 'XXXXXXXXX'

遇到的问题是：如果d表没有满足条件的记录，会导致整个查询没有结果。

请问各位应该怎么解决？

Answer 1

from user a,assinfo b,payable c,gov d
where a.accountno = b.account_no
and b.cert_no = c.addresscode
and d.warmyear(+) = c.warmyear
and b.cert_no = 'XXXXXXXXX'
如果D表没数据的话就关联一下，哪些表没数据，就在where从句加 (+)关联即可