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    <p>By default Entity Framework uses lazy-loading for navigation properties. That's why these properties should be marked as virtual - EF creates proxy class for your entity and overrides navigation properties to allow lazy-loading. E.g. if you have this entity:</p> <pre><code>public class MemberLoan { public string LoandProviderCode { get; set; } public virtual Membership Membership { get; set; } } </code></pre> <p>Entity Framework will return proxy inherited from this entity and provide DbContext instance to this proxy in order to allow lazy loading of membership later:</p> <pre><code>public class MemberLoanProxy : MemberLoan { private CosisEntities db; private int membershipId; private Membership membership; public override Membership Membership { get { if (membership == null) membership = db.Memberships.Find(membershipId); return membership; } set { membership = value; } } } </code></pre> <p>So, entity has instance of DbContext which was used for loading entity. That's your problem. You have <code>using</code> block around CosisEntities usage. Which disposes context before entities are returned. When some code later tries to use lazy-loaded navigation property, it fails, because context is disposed at that moment.</p> <p>To fix this behavior you can use eager loading of navigation properties which you will need later:</p> <pre><code>IQueryable&lt;MemberLoan&gt; query = db.MemberLoans.Include(m =&gt; m.Membership); </code></pre> <p>That will pre-load all memberships and lazy-loading will not be used. For details see <a href="http://msdn.microsoft.com/en-us/data/jj574232.aspx">Loading Related Entities</a> article on MSDN.</p>
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    1. POSolving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException
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    1. USSergey Berezovskiy
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    1. COThanks a lot for your helpful explanation and answer. Actually here I am including three table so I don't know how I can add the three tables with INCLUDE. can you please help me on this please.
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    2. CO@barsan just include all navigation properties one by one. E.g. `db.MemberLoans.Include(m => m.Membership).Include(m => m.LoanProduct).OrderByDescending(m => m.LoanDate);` that will generate JOIN query and return all data at once.
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    3. COThanks a lot lazyberezovsky. I am so grateful to you. You saved me almost a day. From you explanation I am learning more about Entity Framework. Thank you my friend.
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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