I am going to develope a eHelpDesk. This system is to resolve user issues and also to provide them diffirent services.

Like for example if my Photo copier is out of order, I will raise a ticket, by selecting a predefined servie "Maintinance of photo copier" and my problme will be putted forward/resolved by the concerned technician.

I have designed a services table like this

ServiceID
ServiceName
ParenetServiceID
ServiceCode

and so on.........

Now there are some special attribute(s) of each and every service that is specific to that service only.
EXamples:
If the service is "Repair of photocopier" it has an attribute "Counter of photo copier"
And if the service is:
"Installation of Software" It has a unique attribute:
"Asset Traking ID of the computer on which is going to be installed"

There are hundreds of services each having unique attributes. How I can accomodate this requirement in my db Design.

Plz help, our whole project is at risk.

>How I can accomodate this requirement in my db Design.

Third Normal Form!

Thanks for your post!

I know what is third normal form, But will you plz explain it a little bit in my case, As the difficulty in my case is the special attributes depends on an instance of entity, not on the entity itself.

"Service" iz an entity in my case having attributes like
serviceName
sericeCode
serviceParent......

But a special attribute "Counter of photo copier" is an attribute of and instance ("Counter of the copy machine") of the entiry. This attribute has nothing to do with an other instance "Installation of software" of the same entity "Serive".

I cant understant how to apply third normal form to this whole situation.

how bout something like:
pk
typ_o_srvc
value

Check out this Help Desk Data Model.

It will not work for me. I need special attirbutes with each and every service

Try this.

Create a table which will have the common attributes of all services.
Ex:

MainTable - service_id, service_name, service_code ....

then create a one more table which will have 4 columns

SecondaryTable - pk, service_id, attribute_name, attribute_value.

In this way you can store any number of custom attributes for a service type. This is like map in java.

Thnks for your reply, I am going to try this solution.

Can I user Specilization in my Case? Will it be physible to use it here?

eschew obfuscation, espouse elucidation

since it is your database, you can (ab)use it any way you desire to do so.

But i wanted to know the best possible solution.

>But i wanted to know the best possible solution.

First make it work, then make it fancy.

Trying to optimize an implementation that does NOT work, is a waste of effort.