Generic Data Access using LINQ to SQL and C#

Nice Sharing..

Please help me if anyone has solution.

i am getting following error while updating or deleting record.Error : "An entity can only be attached as modified without original state if it declares a version number or does not have an update check policy."

Hello Scott, Thanks for nice example.

i can't attach sql in UPDATE. Can every one help me

Interesting! Could you explain, is it true: Repository "contains static members, so it is difficult to unit test code that calls its members"? Could you recommend the method for unit testing?

I have a InvalidOperationException in the Update method. When I using relational tables (with EntityRef or EntitySet) the method make an error in the Attach operation. Do you know what's happend? thanks.

Hello again, Scott. I am using your code with DevExpress XtraGrid, and the SelectAll method wouldn't work with it. I am getting "...datacontext accessed after dispose...". (This probably happens when XtraGrid tries to get data for child views) The only way I found to fix this is by putting: context.DeferredLoadingEnabled = false; immediately after using(..context..) inside SelectAll. That way, all the related data is loaded during SelectAll, which I don’t like, but at least XtraGrid isn’t trying to reuse the disposed DataContext. Second issue was with Remove method - "An entity can only be attached as modified if it declares a version number or does not have an update check policy". I fixed this by replacing: table.Attach((T)newObj, true); with table.Attach((T)newObj, item); I haven't tested this much, but it seems to work for now. Thanks again for the code, it is still very helpful :)

Hello, first of all thanks for your interesting article about generic DLINQ. but i didn't found in your article Generic Queries i mean a method that has some parameters concerning the Colomn in the target table and its value and it return a set of objects within generic class of course, i think that 's very interresting and useful for code reuseability. Best Regards Thanks

Exactly what I needed, thank you very much.

First,I wanna thank you about this wonderful example...I have downloaded this sample to test it.I've tried to insert an item with a customer id "ZOLA " and it worked perfectly but after that,when I try to delete it ,I was prompted by the following error: "object reference not set to an instance of an object" Do you have any ideas to resolve this issue? Thank you again.

Hi Scott, This generic approach for writing DAL component is really helpful & it's cut down lots of Data Layer Code. Actually I am trying to implement the same concepts using ADO .NET Entity Framework (released in VS 2008 SP1) rather that LINQ but I stuck in some places that I couldn't find out the Entity class at run time since There is no GetTable() method in EntityContext class. So could you pl help me out in implementing the above soln using ADO .NET Entity Framework Sanjay

Scott Thank you very much for this article - I am just now learning LINQ and this is the kind of nice, OO-based use I have been looking for. Many of the quick-and-dirty articles I have seen use way too much database-related code on the client side. This generic DAL approach is more like what I've grown accustomed to in the ADO.Net world. Thanks again for the contribution. Well written and easy to understand your examples.