Divide students in groups based on preferences

Question

1.00/5 (1 vote)

See more:

I have these two tables.

Student Preferences Tables

Student Name------Preference 1------Preference 2------Preference 3-------Group ID
Student A------------Student G-----------Student F------Student G
Student B------------Student H-----------Student K------Student L
Student C------------Student I---------- Student A
Student D------------Student H-----------Student K
Student E
Student F
Student G
Student H
Student I
Student J
Student K
Student L

Groups Table
Group ID
1
2
3

I am creating groups of students, where Preferences = "Preferred Partner/Team Mate". Group Table, Group ID = Group Number (Each group can have min 3 max 4 students ) The way i am trying to implement this is, check for students who have entered 2 or more preferences and make them group. Remaining students with 1, 2 or no preferences can be added together to form groups of 4. Some students may be left out without a group. Any suggestions on implementing this in some other way. It is not necessary that all students have their preferred partner.

Posted 29-Sep-13 0:00am

Mubshir

Add a Solution

Comments

RedDk 29-Sep-13 15:34pm

Repost

http://www.codeproject.com/Questions/660322/Divide-students-in-groups-based-on-preferences

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Wendelius · Accepted Answer · 2013-09-29T00:31:00

Solution 1

Personally I would change the structure of the tables before proceeding further.

Instead of storing the preferences in separate columns, normalize the data and use another table. In this case it would mean that you would have tables like:

Student
-------
- studentid
- name
- ...

StudentPreference
-----------------
- studentid
- preferencestudentid

This would make it easier to later find preferences, handle the changes in preferences and so on.

Posted 29-Sep-13 0:31am

Wendelius

Comments

Mubshir 29-Sep-13 7:37am

I have made changes to my database as you advised. Do you have any suggestions on how can i implement this?

Wendelius 29-Sep-13 7:55am

What are you stuck in?

Mubshir 29-Sep-13 8:35am

I have to approaches in my mind.
First i can check for all students who have entered at least 2 preferences and create a group of them. Than check for students who have 1 preference and create a group and add 1 student who don't have any preference. But i can't figure out how i will be able to avoid situations Like, For example, Student A has added all preferences which include Student B . Student B has also entered 3 preferences which include Student A + 2 different students from Student A's preferences. It is very unlikely that it will happen though.
Second way is like this.
Student A has entered student B as preference. I will check if Student B also has added student a as preference than i will group them together but i have no idea how to achieve this.

Wendelius 29-Sep-13 9:14am

So if I understood correctly, you worry about 'duplicate' references when the reference is both ways? For example:
studentid preferencestudentid
1 2
1 3
1 4
2 1
2 3
2 4

Is this something you want to avoid? If so, you could create a trigger on the table to check if such preference already exists but in opposite way. Also a unique constraint would take care that the sae preference cannot be added twice.

Mubshir 29-Sep-13 9:18am

I get it, thanks

Wendelius 29-Sep-13 9:25am

You're welcome :)