A more OO approach to this would be to create an interface that your
entire object inherits from which are to be persisted to the database.
Public class author : IPersistable
{
....
}
This class should also know nothing about how the data is persisted just
that it contains what is required to get persisted.
You should then have an object that knows about IPersistable and how to
persist this interface to the database.
Public class service
{
Public IPersistable persist(IPeristable)
{
.... this is the were the code for the database persist
would occur
}
}
You could then have a service object work like:
It gives it polymorphic behavior since now you can create a book class
that also inherits from IPeristable and pass that into the persist
method as well. BTW, you will still have to handle the different types
of objects within the persist method but you can create private method
to do this internally and just call the appropriate private persist
based on the type of object passed in. It provides the end programmer a
cleaner solution for data access.
-----Original Message-----
From: Unmoderated discussion of advanced .NET topics.
[mailto:[EMAIL PROTECTED] On Behalf Of Christopher
Reed
Sent: Thursday, July 07, 2005 6:46 AM
To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM
Subject: Re: [ADVANCED-DOTNET] ASP.NET 2.0 ObjectDataSource poor design?
How can you update a data record (or set of records) without passing in
the changed information as parameters?
Christopher Reed
Web Applications Supervisor
Information Technology
City of Lubbock
[EMAIL PROTECTED]
"The oxen are slow, but the earth is patient."
>>> [EMAIL PROTECTED] 4:12:38 PM 7/6/2005 >>>
In a Business Layer with Busines Entities with CRUD Behaviors (has
described here [1] at Cap. 'Defining Custom Business Entity Components
with CRUD Behaviors') typically
1) the Update() method have zero parameters
2) the Update() method is in a Business Entity class say Author, while
the SelectAuthorsByXxx() methods that get filtered lists of authors is
in another Business Entity say Authors class.
But... ObjectDataSource:
1) don't let me set a method with zero parameters to UpdateMethod!
2) don't let me set SelectMethod and UpdateMethod from 2 different
classes!
To use ObjectDataSource in real world application I had do write a
wrapper like this:
public static class AuthorsWrapperForObjectDataSource {
public static List<Author> SelectAuthorsByState(string state, string
sortExpression) {
return AuthorsList.GetAuthorsByState(state, sortExpression);
}
public static int UpdateAuthor(Author author) {
return author.Update();
}
}
I have to write a wrapper for ObjectDataSource also when I have a
Business Layer with Busines Entities without CRUD Behaviors (has
described here [1] at Cap. 'Defining Custom Business Entity
Components').
Am I missing the correct usage of ObjectDataSource or someone else noted
these ObjectDataSource limitations?
TIA (luKa)
http://nullabletypes.sf.net/
http://dev.luca.minudel.it/
http://www.luca.minudel.it/eng/
[1] Designing Data Tier Components and Passing Data Through Tiers,
Microsoft, 2002
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/h
tml/BOAGag.asp
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