Hello experts!

I am looking for an application of following type:

A data management application with dynamic data structure.
Create, Read, Update, Delete (aka CRUD) as basic functions. 
List and Search functionality.

OS: wether web or windows or java.
Storage: based on DB or XML or text-files or whatever (not really important).
Point and click application somehow usable with a windows2k machine.

Following example Scenarios (Use Cases) should be possible with this
application in point-and-click style:

Use Case: Maintain Cars
Create Object "Car"
Add Attrubute Name to Car
Add Attrubute Make to Car
Insert Car (Name="Passat", Make="VW")
Insert Car (Name="C-Class", Make="Mercedes")

Use Case: Add some more Details
Add Atribute Year to Car
Update Car (Year="2000" where Name="Passat")
Insert Car (Name="5er", Make="BMW", Year="2001")

Use Case: Maintain Owners
Create Object "Owner"
Add Attribute Name to Owner
Add Attribute Hand to Owner
Add ReferenceAttribute Car to Owner //this would be a pointer to one
of existing instances of Cars

Add ReferenceCollectionAttribute Owners to Car //this is a
collection-pointer-attribute

Insert Owner (Name="me", Hand="2nd", Car="Passat")

Use Case: Update Data Structure
Change Owner's Attribute Car to ReferenceCollectionAttribute Cars

Use Case: Update Data
Insert Owner (Name="you", Hand="1st", Cars=("C-Class", "5er"))
Delete ("Passat")
Delete ("me") //now 1 owner ("you") and 2 cars ("C-Class" and "5er")
should remain in the application

Application should not insist on entry of all data, in our example
there would be Cars without any Owners and Owners without Cars.

Application should automatically change/update the
database-table-structure if a database is used.

Application should automatically change/update the GUI.

It is not critical but would be nice, if the application would not ask
me for the data type of attributes and select one automatically. If
user enters a digit - select integer, if next entry contains
characters - update data structure with changing this particular
integer-attribute to string-attribute.

Please give me the urls and short description how to run the scenarios, if
this is not obvios (i.e. you know the way how to do this with
MS-Access or XML-Spy).

Is your attribute list fully dynamic?  For example, will there be a
case like Owner.AddAttribute("GirlfriedPrefereFarrari", true)?  If
yes, it sounds like a object oriented database, which seldom used in
production environment.  Otherwise, it's just a simple database
application.

BTW, although we say second hand owner, nHand is actually a car attribute.

Thanks for your comment wellcum-ga.

Yes, the attribute list should be fully dynamic. Especially the
existence or non existence of an attribute should be dynamic. The data
type of attributes is not that important, it would be nice, but not
crucial. I would be happy, if every attribute would be of string type.

But if you think, that this sounds like simple database application,
can you name couple of them, where you can go through the suggested
scenario (sequence including all use cases) without going down on
SQL-statements to change the database-structure? Using the "official"
GUI of the particular application.

Thanks for correcting me concerning the nHand-Attribute.

I actually worked on the design of a similar application, but I was
limited to using only a relational database.   I have a very good
database schema for doing such a task, but I would not recommend using
it if you can use an OO database.  With a relational database you will
run into performance issues and you will also have to write very
complex queries to get information about related objects.

If you need to create objects / attributes on the fly you are better
off with an OO database.

If you wanted to do this in a relational database, I would suggest
that you re-think the true nature of the application.   Can you get
away with identifying solid base tables and attributes, and then add
new tables / attributes as necessary in the future.   Of course this
evolution will require additional programming resources when the
changes occur.

It's simple if the attribute list is fixed.  I mentioned OO database
because it sounds like an experimental project.  I heard Microsoft
Visual FoxPro has OO abilities, but never tried it.  You can use XML,
which is flexible but then performance could be an issue.

Of course, you can get away with anything using relational database. 
Here's a sample database that may help:
http://www.geocities.com/tyzh/crud.jpg   You don't have to change
database structure, just need a few extra joined queries.  Your use
case would be: NewCarAttribute, NewCar, AddCar_Attribute,
NewOwnerAttribute, NewOwner, AddOwner_Attribute, Car_OwnerTransaction,
just to name a few.

The real challenge is the interface, espcially when the list of
attributes are extremely unbalanced.