Question

我想访问子查询中的st.Gr_number列但这给了我错误

ORA-00904：“ ST”。“ GR_NUMBER”：无效的标识符

    Select st.Gr_number,
st.STUDENT_ID, st.course, 
st.Student_Name,cr.course_name,
st.Status as Active,
st.GR_NUMBER as Fee_Detail,
(Select sum(nvl(r.amt, 0)-nvl(f.fee_amount, 0)) as Current_Balance
from FEE_SCHEDULE f 
full outer join (select gr_number, to_char(pmt_date,'yyyymm') pmt_month, sum(nvl(pmt_amount,0)) amt 
                 from FEE_PAYMENT_POSTED
                 Where pmt_type = 'FEE'
                 and   gr_number = st.Gr_number
                 group by gr_number, to_char(pmt_date,'yyyymm')
                ) r 
             on f.GR_NUMBER=r.GR_NUMBER and f.SCHEDULE_MONTH=r.pmt_month

where nvl(f.gr_number,r.gr_number) = st.Gr_number
) currentBalance

from student st inner join course cr on cr.course_id=st.course
where st.student_id=:P166_STUDENT_ID and upper(st.Status)='STUDYING';

Answer 1

在内部查询中，您尝试使用st.GR_NUMBER，但仍未定义它在外部查询中的使用。

这是问题所在的gr_number = st.Gr_number。

Answer 2

此行导致错误：

            and   gr_number = st.Gr_number

尽管很难从格式上分辨出来，但这嵌套了两个层次：

select . . . ,
       (select . . .
        from . . . 
             (select . . .
              from . . . gr . . .
              where . . . and
                    gr_number = st.Gr_number
             ) level3
       ) level2
from . . . st . . .

Oracle的范围规则仅允许将表引用识别为一级。因此，在level3中，您可以引用level2，但不能引用外部级别。

您有一个非常复杂的查询。没有办法知道这是否是唯一的问题，所以我什至不会尝试修复它。

我建议您通过简化查询问另一个问题。

带有子查询的无效标识符

2 个答案: