getting wrong result - sql

Question

Hospital_Visit
hid pid HospitalName DoctorId
41 1 abc 1
42 2 xyx 2
Patient_Master
pid PatientName
1 jill
2 rosy
Doctor_Master
DoctorID DoctorName
1 John
2 Jack
Hospital_Study
sid hid exam status
1 41 jjj sfvn
2 41 fks jdjd
select Hospital_Visit.Pid,PatientName,DoctorName from Patient_Master
inner join Hospital_Visit on Hospital_Visit.pid=Patient_Master.pid
inner join Doctor_Master on Doctor_Master.DoctorID= Hospital_Visit.DoctorID
inner join Hospital_Study on Hospital_Study.hid=Hospital_Visit.hid
Pid PatientName DoctorName exam status
1 Jill John jjj sfvn
2 rosy John fks jdjd
**
//Correct output i want
Pid PatientName DoctorName exam status
1 Jill John jjj sfvn
2 rosy Jack fks jdjd
**
i am getting wrong result repeting doctor
name in result because of inner join hid on Hospital_Visit and Hospital_Study
How can i takle this problem
(DTU Edit - Current sample data in usable form):
create table Hospital_Visit(hid int,pid int,HospitalName char(3), DoctorId int)
insert into Hospital_Visit(hid, pid, HospitalName, DoctorId) values
(41, 1, 'abc', 1),
(42, 2, 'xyx', 2)
create table Patient_Master(pid int, PatientName char(4))
insert into Patient_Master(pid, PatientName) values
(1, 'jill'),
(2, 'rosy')
create table Doctor_Master(DoctorID int, DoctorName char(4))
insert into Doctor_Master(DoctorID, DoctorName) values
(1, 'John'),
(2, 'Jack')
create table Hospital_Study(sid int, hid int, exam char(3), status char(4))
insert into Hospital_Study(sid, hid, exam, status) values
(1, 41, 'jjj' ,'sfvn'),
(2, 41, 'fks' ,'jdjd')

Answer 1

With the sample data given right now (revision 4), it's impossible to get the output you want.
Right now, your query returns this:
Pid PatientName DoctorName
1 jill John
1 jill John
What you want is this:
//Correct output i want
Pid PatientName DoctorName exam status
1 Jill John jjj sfvn
2 rosy Jack fks jdjd
...but the data in the Hospital_Study table doesn't match this, because both lines have hid = 41:
Hospital_Study
sid hid exam status
1 41 jjj sfvn
2 41 fks jdjd
So they both reference the first row from the Hospital_Visit table, which belongs to the patient named "Jill".
--> with this data, it's impossible to select the patient named "rosy", because there is no row in the Hospital_Study table that refers to rosy's visit (hid = 42).
To get the desired output, the data in the Hospital_Study would need to look like this:
Hospital_Study
sid hid exam status
1 41 jjj sfvn
2 42 fks jdjd
/\
||
this is different
With this data, and the exact query from your question, you get this result:
Pid PatientName DoctorName
1 jill John
2 rosy Jack

Answer 2

I have a doubt on your join
inner join Hospital_Study on Hospital_Study.hid=Hospital_Visit.hid
Hospital_Study.hid is Foreign key that's right but Hospital_Visit.hid is a primary key or is it a foreign key.
If Hospital_Visit.hid is a foreign key of then you have to add one more inner join on your Hospital's Master table (Hospital_Master).