使用时执行查询时出错

Question

This the query that we are trying to execute

select
     *
from pub_int_marks
where pub_int_marks.is_active = 1
having count(select
                  student.id
               from student
              inner join prev_class_data on prev_class_data.student_id = student.id
              inner join class_scheme on student.class_scheme_id = class_scheme.id
              where (prev_class_data.class_id = pub_int_marks.class_id or class_scheme.class_id = pub_int_marks.class_id)
              and student.id = 15) > 0

Both the inner query and the outer query works fine independently, but when combined its giving error. What is wrong with the query?

Answer 1

I'm not sure what exactly your query is supposed to be doing, but I don't think the subquery with a HAVING is the way to do it.

What about something like this?

select pub_int_marks.*
from student
inner join prev_class_data 
    on prev_class_data.student_id = student.id
inner join class_scheme 
    on student.class_scheme_id = class_scheme.id
inner join pub_int_marks
    on prev_class_data.class_id = pub_int_marks.class_id or class_scheme.class_id = pub_int_marks.class_id
where student.id = 15

or if you don't want to use an OR in a JOIN ON:

select pub_int_marks.*
from student
inner join class_scheme 
    on student.class_scheme_id = class_scheme.id
inner join pub_int_marks
    on class_scheme.class_id = pub_int_marks.class_id
where student.id = 15

union

select pub_int_marks.*
from student
inner join prev_class_data 
    on prev_class_data.student_id = student.id
inner join pub_int_marks
    on prev_class_data.class_id = pub_int_marks.class_id
where student.id = 15