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    <p>You need to call</p> <pre><code>samplesDbEntities.SaveChanges(); </code></pre> <p>before requerying for the object.</p> <pre><code>var samplesDbEntities = new SamplesDBEntities(); var blogId = Guid.NewGuid(); samplesDbEntities.Blogs.AddObject(new Blog() { BlogID = blogId }); samplesDbEntities.SaveChanges(); var objectSetResult = samplesDbEntities.Blogs .Where(p =&gt; p.BlogID == blogId) .SingleOrDefault(); </code></pre> <p><strong>Update</strong></p> <p>The reason why you are not getting the added user back in objectSetResult is that calling the SingleOrDefault method of an IQueryable object results in a database query (an actual SQL query string is generated accoding to the "where" condition, etc.), and since the object is not (yet) in the database, it doesn't get returned. The new object is, however, attached to the context, and it's EntityState is set to "Added". According to MSDN, objects in the Added state do not have original values in the ObjectStateEntry. The state of objects inside an object context is managed by the ObjectStateManager. So if you want to check that the object has really been attached, you can fetch it by calling GetObjectStateEntry:</p> <pre><code>var samplesDbEntities = new SamplesDBEntities(); Blog blog = new Blog() { BlogID = Guid.NewGuid() }; samplesDbEntities.Blogs.AddObject("Blogs", blog); Blog addedBlog = (Blog)context.ObjectStateManager.GetObjectStateEntry(blog).Entity; </code></pre> <p>Also note that the EntityState of the retrieved object is "Added".</p> <p>To sum up - regarding your initial question about whether it is a correct implementation of UnitOfWork, I don't see why not. It does indeed maintain a list of objects and tracks the changes, etc, etc. The issue you encountered, however, is related to the fact that the you are fetching data from the underlying provider, rather from the list of objects currently attached to the context.</p>
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    1. POIs Entity Framework ObjectContext correct implementation of Unit Of Work Pattern?
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    1. USYakimych
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    1. CO-1 cos this is doesn't answers on the exact question "Is Entity Framework ObjectContext correct implementation of Unit Of Work Pattern?"
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      1. USRestuta
    2. COFair enough. See updated answer.
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    3. COMy use case is that an entity gets added and retrieved before the persistence would occur - what is the point of UoW if I have to persist every entity on its own and not in batch? As for the update code , don't you think the fact that I have to know that I need to use ObjectStateManager is bad (leaking infrastructure)? Not the case in my trivial sample, but that "get" can occur in completely different place where I wouldn't know if something is added. Why that won't be encapsulated inside of the OBjectSet itself (like UoW should do) and just being recognized during the persistence?
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      1. USNikola Malovic
 

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