Hi there,

Now im not too good with MS access and even worse with ER diagrams, i was just hoping someone could help me on this project.

This is what i need to do:

1) An ER diagram showing all entities, relationships, multiplicity and membership class.

2) A set of well normalized tables (table types) showing corrent posting of keys to maintain referential integrity and all the data necessary to suport the processing indicated in the scenario in Appendix B

3) A set of 'assumptions' that you feel are necessary to explain your ER modelling/design decisions.


Appendix B

A team of forensic scientists wish to create a 'Crime Scene' database to record details of crime scenes they have worked on. They are concerned that they are failing to take advantage of modern database technology either in recording the findings of their investigations or in searching past cases to seek similarities between cases.

The following is an extract from an analysis report

When investigators arrive at a potential crime or investigation scene they firstly establish whether or not the scene has been changed by anyone. If the scene has been changed they record what changes have occurred and details of those that reported the changes to them. They then record the following information about the scene:

Crime details including:
Date
Time (start and end time)
Location
Weather
Name and contact details of the lead Police Officer if involved (if the police are involved)
Investigators name and contact details of any organisational representitive
Catergory of crime (commercial (1), fraud (2), violence (3) computer(4))
For crimes of violence we record additional details about the incident including weapon used severity of injury inflicted, etc.
We also record a list of items removed for further investigation.
We also record a list of crime scene observations (short comments) that may be used later to inform our analysis.

At a later date we also add:
List of suspects and contact details
List of witnesses and contact details
We also need to record the end date of a crime investigation and outcome if known to us.

End of analysis report


Ok sorry this is so long, its just i didn't want to miss anything that might be cruicial.

Thank you in advance if anyone can help.

Ive had another look at this and can't figure out where to start, if anyone can help me start it would be much appreciated.

Thanks.

start by identifying the entities

and don't hold your breath getting a lot of help here, none of us is really all that keen on helping with school assignments when the student shows no effort

No offence but that tone isn't too helpful either, im a university student studying Forensic Science, this is the only IT class we have as everything else is science work. I've looked on websites and have struggled to find the relevant information i need to explain this.

I can assure you that posting here was a last resort, not for my work to be "done for me", but to ask advice from those who obviously know this alot better than me and maybe get a helping start.

Sorry if my post caused any inconvenience

okay, i can understand your frustration

start by identifying the entities

here's a good tutorial --> http://www.utexas.edu/its/windows/da.../datamodeling/

Thank you, im going to have a look through that tutorial and hopefully sort this, thanks again.

Hi again,

Ok im just doing my preliminary tables, im just wondering is there are freeware that i can use for my diagrams?

there sure is

http://databaseanswers.com/modelling_tools.htm

Thank you

Btw any suggestions from that list for a beginner to ERD's

ok ive started to sort my entities like you said and these are the ones ive come up with so far, the entities being in bold. I aren't too sure what to do about violence though, as im sure it goes under crime but then that also has information required for it.

crime details

ID
Time
Location
Weather
ContactName
ContactAddy
Invesname
Invesorganisational
Categoryofcrime


violence

ID
CrimeID
Weapon
Injury

observations

ID
CrimeID
Contactname
Comments

items

CrimeID
Itemname
Reason

Ok guys don't laugh but how does this look

http://www.dbmoulders.co.uk/erd.doc

Download and install this for your operating system

http://www.fabforce.net/downloads.php

It's free. Post screeshots.


Your ERD looks okay.

Now you have to create a logical model.