C# - Are Repositories Useful Without Domain Driven Design?
Mar 9, 2011
Assuming my application did not warrant a full blown DDD setup, would Repositories still be useful? I like the way they shield from implementation details (such as use of Entity Framework) underneath. However Repositories tend to be tied to Aggregate Roots (the concept is still a holy grail to me) by definition.
I suppose the question could also be put as such: if I have a typical 3-tier application, with a business layer facade consisting of "logical grouping" classes based on functionality (rather than aggregate roots as in DDD) such as TradingManager and ContactsManager, would it make sense to also create "logical grouping" repositories. Or perhaps a Data Access Object, which I believe is like a Repository without the aggregate root requirement. Of course I will still have a Model (EF POCOs) that will be passed up and down between the layers.
Also, is what I just described would be considered as a Transaction Script approach? It's certainly not DDD, and not Active Record. I'm not even sure if Active Record exists with EF4 like it does with Nhibernate.
I am trying to understand how others structure n-layered applications when they do not follow DDD.
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Aug 7, 2010
I want to know what is the advantages of using aggregates in c# for design patterns.
suppose i have tree tables
Member(M_Id,M_Info)
Bid(B_Id,B_Info,M_Id,Item_Id)
Item(Item_Id,Item_Info)
"One member can place more than one bid on more than one item."
so there is one to many bidirectional association between Bid and Member table.
And one to many association between bid and item table Now According to defination of aggregates in this case Item table is the root of aggregate item and item has aggregation with bid table.
and bid table holds unidirectional reference to member table and hence only bid table has access over member table.
But ultimately this will also map in database same as without using aggregate then what is use of aggregates?
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Jan 17, 2010
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Dec 6, 2010
Could someone explain what happens to the Repositories that are created when they are no longer needed? Are they automatically disposed of, or should we dispose of them manually?
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Apr 13, 2010
I've been reading up on MVC 2 and the recommended patterns, so far I've come to the conclusion (amongst much hair pulling and total confusion) that:
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Aug 17, 2010
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Csharp Code:
using (IUnitOfWork worker = new UnitOfWork()){// session and transaction are now both set
// save changes to three itemsworker.SaveOrUpdate(item1);worker.SaveOrUpdate(item2);worker.SaveOrUpdate(item3);
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// delete the fourthworker.Delete(item4);
// all pending operations are commited or rolled back as a single unit (if one fails, all are rolled back), and then disposed, along with the session}
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[Code]....
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[code]...
EDIT:
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[Code]....
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