Database Design

Whether my database design is right?

Please support our Database Design advertiser: PostgreSQL or MySQL? Compare and contrast the two most popular open source databases

Thread Solved

•

Join Date: Aug 2008

Posts: 22

Reputation: dharam_05 is an unknown quantity at this point

Solved Threads: 0

dharam_05

Offline

Newbie Poster

Whether my database design is right?

Aug 7th, 2008

I have to create database of student having different subjects and marks in respective subjects.

Now many students will many subjects so there is many to many relationship.

My database design:
Table 1:

Student table
(PK)Stud_id, Stud_name

Table 2:

Subject table
(FK)Stud_id, Sub_id, Sub_name, Marks.

Table 3:

Stud_Sub table
Stud_id, Sub_id

1) is this design is right or wrong?

2) Secondly i want to find name of the student who scored second highest marks.

Last edited by dharam_05; Aug 7th, 2008 at 3:45 am.

•

Join Date: Dec 2004

Posts: 4,192

Reputation: peter_budo has much to be proud of

Solved Threads: 485

peter_budo peter_budo is offline

Offline

Code tags enforcer

Re: Whether my database design is right?

-1

Aug 7th, 2008

Why don't you have only (PK)Sub_id and Sub_name in Subject table
and
(FK)Stud_id, (FK)Sub_id, Marks in Stud_Sub table?

Learn to see in another's calamity the ills which you should avoid.
Publilius Syrus
(~100 BC)
LJC - London Java Community, Graduate & Undergraduate Software Development Community, JAVAWUG (Java Web User Group), The London Android Group

•

Join Date: Aug 2008

Posts: 22

Reputation: dharam_05 is an unknown quantity at this point

Solved Threads: 0

dharam_05

Offline

Newbie Poster

Re: Whether my database design is right?

Aug 7th, 2008

Ok so there is no need of stud_id in sec table?
other than that thing are ok in database?
But i want to calculate sec highest marks of the student.

•

Join Date: Dec 2004

Posts: 4,192

Reputation: peter_budo has much to be proud of

Solved Threads: 485

peter_budo peter_budo is offline

Offline

Code tags enforcer

Re: Whether my database design is right?

-1

Aug 7th, 2008

•

Originally Posted by dharam_05

But i want to calculate sec highest marks of the student.

You need to run query that will look up all the students with their marks of given subject. Sort them descending order and ask for second of them. So try to come with some query and if doesn't work out post it and we may have go on it.