I have two tables, gradereport and student

The gradereport table has the studentNo which is a foreign key from the table student and it also has the grades for each student,

I must query the gradereport table to find out which students do not have all grade 'A' in the courses they took.

If they have any grades that are not 'A' then they should not be included in the results.

How can I query the table gradereport to find students who do not have all 'A's in their courses.

gradereport table

student table

Students who do not have all A grade could be found as

select s.*,
gr.section,
gr.grade 
from student s 
join gradereport gr on gr.studentNo = s.studentnumber 
group by s.studentnumber,gr.section 
having sum(gr.grade='A') <> count(*) ;

Or if you dont care about the section then

select s.* 
from student s 
join gradereport gr on gr.studentNo = s.studentnumber 
group by s.studentnumber 
having sum(gr.grade='A') <> count(*)

Try this:

SELECT student.name, student.number
FROM student, gradereport
WHERE student.number = gradereport.StudentNumber
AND gradereport.Grade != 'A'

Find all students which have at least one grade A:

SELECT DISTINCT `StudentNo` FROM `gradereport` WHERE `Grade` = 'A'

Finding the oposite results:

SELECT `StudentNo` FROM `gradereport` WHERE `StudentNo` NOT IN (SELECT DISTINCT `StudentNo` FROM `gradereport` WHERE `Grade` = 'A')

you can do an exclusive check like so

SELECT distinct studentno FROM gradereport gr
WHERE gr.grade = "A"
AND NOT EXISTS
(   SELECT 1
    FROM gradereport
    WHERE grade <> "A"
    AND studentno = gr.studentno
)

DEMO

you could also do an exclusive join (my preference)

SELECT DISTINCT gr.studentno
FROM gradereport gr
LEFT JOIN gradereport gr1 ON gr1.studentno = gr.studentno AND gr1.grade <> "A"
WHERE gr1.studentno is null 

BETTER DEMO

I'd do something like this:

SELECT DISTINCT StudentNo FROM gradereport GR WHERE NOT EXISTS ( SELECT 1 FROM gradereport GR2 WHERE GR.StudentNo = GR2.StudentNo AND GR2.Grade != 'A' )