While the model is being built, the context cannot be utilized.

c# entity-framework

Question

In my application I receive the following error:

The context cannot be used while the model is being created.

I'm not sure what this means. I have done everything as normal and usually it works but for this one it isnt. Below is my code:

App.config:

 <connectionStrings>
    <add name="DatabaseContext" connectionString="Data Source=./SQLEXPRESS;Initial Catalog=ProjectCode;Integrated Security=SSPI;" providerName="System.Data.SqlClient" />
 </connectionStrings>

Products.cs:

class Products
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
}

DatabaseContext.cs:

class DatabaseContext : DbContext
{
    public DbSet<Products> Products { get; set; }
}

Program.cs:

DatabaseContext context = new DatabaseContext();

try
{
   var products = context.Products.ToList();

   foreach (var item in products)
   {
      Console.WriteLine(item.ProductID + " : " + item.ProductName);
   }
      Console.ReadLine();
}

The line is fails on is var products = context.Products.ToList();

Any ideas what could be causing this? I have set up 2 products in my database so it should be outputting them.

EDIT

Here is my whole App.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.3.1.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  </configSections>
  <connectionStrings>
    <add name="DatabaseContext" connectionString="Data Source=./SQLEXPRESS;Initial Catalog=ProjectCode;Integrated Security=SSPI;MultipleActiveResultSets=true" providerName="System.Data.SqlClient" />
  </connectionStrings>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="Data Source=.\SQLEXPRESS; Integrated Security=True; MultipleActiveResultSets=True" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>
</configuration>
1
27
3/17/2012 2:23:09 PM

Accepted Answer

In your App.Config file under connectionstrings you had a forward slash (./SQLEXPRESS). Change this to a backslash .\SQLEXPRESS like so:

<add name="DatabaseContext" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=ProjectCode;Integrated Security=SSPI;" providerName="System.Data.SqlClient" />
17
3/17/2012 5:28:06 PM

Popular Answer

I have experienced this issue in the past and usually it was due not using the latest version + referencing issue.

Try and get the newest EF version from NuGet for all your projects and see if the error goes away:
http://blogs.msdn.com/b/adonet/archive/2012/02/09/ef-4-3-released.aspx

UPDATE
Another reason for this error can be that while you create the context the first time and therefore cause the model to be created you create another context on a separate thread. You will have to wait for other context instances to be created after the model creation has completed.



Related Questions





Related

Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow
Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow