Hi,
If the only different among the different kinds of contacts is the type,
and the type is not dynamic I would suggest you to use an enum:
public enum ContactKind { Employee, Customer, Vendor }
then you can declare ContactType of that type:
public ContactKind ContactType{
get {}
set {}
}
By default the enum is of type int, so at load type you can cast it back
from an int :
contacttype = (ContactKind )( Convert.ToInt32( reader["ContactKind "]));
//reading from a datareader
and at save you can do the opposite:
com.Parameters.Add("@ContactKind ", SqlDbType.Int).Value =
(int)this.contacttype ;
Hope this help,
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"msnews.microsoft.com" <aa7im@yahoo.com> wrote in message
news:ec3Ra7nSDHA.3192@tk2msftngp13.phx.gbl...[color=blue]
> What is the best solution for the following scenario:
>
> I have a contacts database and I am creating the business layer obects to
> access my data objects. (So the DB is invisible to the Business Layer
> consumer)
> Each contact can be of some type "Employee, Customer, Vendor, etc." . The
> contact types are also stored in a table in the DB.
>
> So in the business layer I am trying to a make a decision on how to model[/color]
my[color=blue]
> object flow. Here are some examples:
> ---------------------------------
> Method One:
> Contact objPerson = new Contact();
> objPerson.Name = "Jose";
> objPerson.Address = "666 somewhere street";
> objPerson.City = "somecity";
> objPerson.ContactTypeID = 3; //Each
> objPerson.Save();
>
> Problem:
> If the ContactTypeID does not exist in the DB there will be an error[/color]
thrown[color=blue]
> by the DB. Also, when a user type objPerson.ContactType, I want it to
> return a "ContactType" object.
>
> --------------------------------
> Method Two:
> Contact objPerson = new Contact();
> .... Set Generic Properties ...
> ContactType objContactType = objAppFactory.GetContactType(3);
> objPerson.ContactType = objContactType;
>
> Problem:
> This method allows me to throw an error as soon as the user tries to[/color]
lookup[color=blue]
> a nonexistent ContactTypeID before assigning to the Contact. However, I
> have the extra round trip to the DB. Seems silly
>
> -------------------------------
>
> Method Three:
> I can could provide to ways of setting the ContactType.
> objPerson.ContactType = objApp.GetContactType(3);
> or
> objPerson.SetContactTypeID(3);
>
> Problem:
> Seems dumb
>
> ------------------------------
>
> Method Four:
> ContactType objEmployee = new ContactType();
> Contact objPerson = new Contact();
> objPerson.Name = "Jose";
> objPerson.Address = "666 somewhere street";
> objPerson.City = "somecity";
> objEmployee.AddContact(objPerson);
>
> Problem:
> If the user attempts objPerson.Save() before it has been added to a
> "ContactType" the DB will throw an error becuase it does not have a
> "ContactTypeID". I can Validate the object before I attempt to save to[/color]
the[color=blue]
> DB by checking to see if the ContactTypeID property has been set; if not,[/color]
I[color=blue]
> can throw and exception with something like: "A Contact must be first[/color]
added[color=blue]
> to a ContactType before it can be saved to the DB".
> Also, when I add the Contact to objEmployee, does the[/color]
objEmployee.AddContact[color=blue]
> method need to reoginize that objPerson has not been saved yet, and then
> automatically save it to the DB?
>
>
> Thanks. I am just trying to figure out a standard for accomplishing this[/color]
so[color=blue]
> I can replicate the concept into projects I am working on....
> Josh
>
>[/color]
