Unable to retrieve metadata for unrecognized element 'providers' when adding a controller in VS 2013

Hi,

I was trying to add a new controller in my project using Visual Studio 2013. I was using Code First Entity Framework for my data access. I tried to build and clean the project few times before adding the new controller; but still was getting this error message when  adding a new controller to my web api project.

Here is the error message:

The solution is the following:
1) Open the web.config file in your project.
2) Scroll down until you see entity framework section.
3) This is how it will be looking:

<entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>

4) Remove the providers section.
5) Save and you will be able to add new controllers!

Hope this helps!

One or more errors occurred while processing template 'Entity.tt'. Using Reverse Engineer Code First in VS 2012 Update 1

Hi,

Using VS 2012 Update 1, I was doing some changes in my database schema and when i try to reverse engineer code first my updates i was getting the following error:

One or more errors occurred while processing template 'Entity.tt'.

In the output window, VS listed that System.Xml and System.Xml.Linq exist on 2 different paths, one where the .NET framework is installed and the other one is pointing to the Siliverlight 5 DLLs in the GAC.

While it is reported as a bug in Microsoft Connect website, I was trying to remove the link to the Silverlight 5 Dlls that i'm not in need when i reverse engineer code first my EF files to apply my DB changes.

To fix this problem: 
1) Open the following directory:

C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\Extensions\Microsoft\Entity Framework Tools\Templates\Includes

2) Take a backup from EF.Utility.CS.ttinclude or the VB version based on the your project language you are using.

3) Open the notepad in an administrator mode.

4) Open the CS.ttinclude file.

5) change the following 2 lines:

<#@ assembly name="System.Xml" #>
Change it to:
<#@ assembly name="System.Xml, Version 4.0.0.0, Culture=neutral" #>

<#@ assembly name="System.Xml.Linq"#>
Change it to:
<#@ assembly name="System.Xml.Linq, Version 4.0.0.0, Culture=neutral"#>

6) Save the file.

7) Right click on the project that has the EF files and click on Reverse engineer Code First.

8) bingo! you will get your database updates with no errors.


Let me know if you have any issues with this.

Calling Stored procedure from EF takes long time and times out!

Hi Folks,
 
I was going through an interesting performance issue when calling a stored procedure from my web application more than one time and the WCF was timing out because of the stored procedure execution takes long time to execute.
 
At the first, I have a parameterized stored procedure that takes different parameters. First time it executes as expected.
 
The second time, the EF calls the stored procedure and i don't get any results back to my application. i thought there is an issue in the Stored procedure but no because the stored procedure works as expected from the SQL management studio.
 
 
This means, there is something is going on between the EF bindings and getting results to mapped views/entities we have in the DBML file.
 
I was searching and trying to find any clue why this could happen ? I tried different things but it didn't work, until i read the following articles about performance issues in EF:
 
http://msdn.microsoft.com/en-us/library/cc853327.aspx
 
I realized that i don't have issues in terms of the SQL performance, but EF does have some overhead on executing any stored procedure and getting the results back to mapped view objects. Since this search stored procedure return list of objects to one of my entities, i want to know why does it take long time to execute and i don't get my results back ?!
 
I found the solution for my problem by doing 2 steps:
 
1) Since i don't want to track any loaded objects for my entities, i added the following merge option with No Tracking when i call my stored procedure.

C# Code:

this.ObjectContext.Search(EmpId,EmpName, DeptId,DeptName, System.Data.Objects.MergeOption.NoTracking).ToList();


2) Since SQL Server has a known performance issue called Paramter sniffing, which means the SQL Server engine allows to compile the plan for the stored procedure and reuse this plan for subsequent calls of the same stored procedure with different paramters! and this was my case, i pass long list of parameters but with different values. the first time executes as expected because the server chose to compile the plan with the results but the second time it re-uses the compiled plan which might not work well with the results that i want and this takes long time to get the expected results!
 
This is a known issue when your stored procedure inlcudes Like keyword in your queries and you use the input paramters directly to filter your results without using other temp paramters assigned from the input parameters.
 
What you need to do is to force SQL to compile the query each call and not to use a precompiled plan and this can be accomplished by using : RECOMPILE query hints along with your query. This is supported in SQL 2005 and above. I'm using SQL 08 R2 server.

Select * FROM myView
WHERE DeptName like '%' + @DeptName+ '%' 
OPTION (RECOMPILE); -- This enhance the performance query and fix the parameter sniffing issue for multiple calls stored procedure.

 After these 2 changes, I ran my web application, the application works as expected and no times out for the stored procedure that is being called twice!

Hope this helps.


Reference:
1) Table Hints in SQL Server:
http://msdn.microsoft.com/en-us/library/ms181714.aspx

2)  Paramter Sniffing in SQL Enginer:
http://blogs.technet.com/b/mdegre/archive/2012/03/19/what-is-parameter-sniffing.aspx


 
 

What do you expect from Entity Framework 6 Alpha ?

Hi,

 

I was reading the MSDN magazine March 2013 and i found an article by Julie Lerman about EF 6 Alpha features.

 

If you haven't had the chance to read the article, here is a summary of this article for .NET developers and architects:

 

1)      EF 6 will be supporting multiple schemas. So in your dbml file you will be able to reference and import multiple schemas in your database.

 

Julie has written a detailed article about this feature, here is the link for this:

http://thedatafarm.com/blog/data-access/digging-in-to-multi-tenant-migrations-with-ef6-alpha/

 

2)      EF6 will be supporting the asynchronous processing (Async).

Since we have Asynchronous pattern supported in .NET 4.5. The EF 6 will be bringing some of these features by having: SaveChangesAsync(), ExecuteSqlCommandAsync and FindAsync() functions that don't block the UI while executing and you will be able to write asynchronous code in your application in EF 6.

 

For Linq to Entities, they have added bunch of other Async methods for enumerations such as: ToListAsync(), FirstOrDefaultAsync(), MaxAsync().

 

This is a very important feature especially for Silverlight, WPF and Windows Phone developers in addition to web developers.

 

3)      Enum and Spatial support

EF 6 will be supporting enums and Spatial data types. Unlike earlier version where dependent on the .NET framework you are using/targeting. The new EF 6 will be supporting this no matter which .NET framework you are targeting. So you can use enums and spatial support even you are targeting .NET 4.0 framework that doesn’t support certain EF 6 features.

 

Hope this helps.