Scenario Cause An UpdateException In EntityFramework While Calling SaveChanges?
Jan 27, 2011
SaveChanges can generate an UpdateException when an object added to the ObjectContext cannot be successfully created in the data source. This can happen if a row with the foreign key specified by the relationship already exists. When this occurs, you cannot use Refresh to update the added object in the object context. Instead, reload the object with a value of OverwriteChanges for MergeOption.
In a table, a foreign key column can have a single value multiple times. e.g. DepartmentID foreign key in Users Table: More than one User can have same DepartmentID foreign key.
So how can this cause an UpdateException ?
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Apr 30, 2010
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Nov 7, 2010
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Dec 11, 2010
I am using ADO.NET Entity Framework data model for my ASP.NET MVC project. I am trying to insert into multiple tables and called .SaveChanges() method. It doesn't throw any exception and doesn't insert into these tables.
What could be wrong here?
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Oct 28, 2010
I have Create and Edit forms for Categories. Columns are Id, CategoryName, Order, CreatedOn. On Create form I save the values for all but on Edit form I need to change only CategoryName. Below is the code. Problem is that on Edit form only CategoryName field exists which on submit button is passed to Edit Action. Whenever I update Order and CreatedOn becomes null because the values are not returned from form. Someone tell me any good approach how to Updated selected values in EF. Below is code.
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[Code]....
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Dec 30, 2010
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Item
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Price
Order
Number
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<asp:EntityDataSource ID="eds" runat="server" ConnectionString="name=NDSEntities"
DefaultContainerName="NDSEntities" EnableFlattening="False" Include="Items"
EntitySetName="Orders"></asp:EntityDataSource>
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<%# Eval("Number") %>
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How should I go about getting the sum of the prices of the items?
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Next
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form.UpdateModel(userObj),
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Jun 14, 2010
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Jan 15, 2010
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<ItemTemplate>
<%# Eval("CategoryID") %> - <%# Eval("Name") %>
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<ItemTemplate>
<%# Eval("CategoryID") %> - <%# Eval("Name") %>
</ItemTemplate>
</asp:Repeater>
</ItemTemplate>
</asp:Repeater>
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to:
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Using .NET 4.0 BETA 2
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Jul 6, 2010
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Heres my code
[Code]....
Heres the ClientViewModel :
[Code]....
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Cannot implicitly convert type 'AdminMVC.Models.Clients_Username' to 'System.Collections.Generic.List<AdminMVC.Models.Clients_Username>'
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I found many different ways to implement it, but what the best practice. May be you can point me in right direction.
Application Web based, MsSQL 2005, .NET 3.5, Server 2003.
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