I'm in the process of converting the existing .Net framework project that uses EF 6 with Database First approach (EDMX) file to .Net Standard 2.1 which connects to SQLDB hosted on Azure.
Existing EDMX file has a constructor (auto generated) that accepts ConnectionString as given below -
public TestDatabaseConnection()
: base(ConfigurationManager.ConnectionStrings["TestDatabaseConnection"].ConnectionString)
{
}
This is breaking for two reasons -
ConfigurationManager.ConnectionStrings works only in .Net framework projects and throw runtime errors in the .Net Core project (for eg- ConfigurationManager.ConnectionStrings returns null).
I need to make changes to the above code to use the AppAuthentication nuget as mentioned in the MSDN docs here
So, what are the options available in order to make this work so that I could use the same nuget package for connecting to the database via EF 6 (database first) for both .net framework and .net core projects?
Is the only available is to convert to Code first and make the necessary changes as mentioned in the above MSDN link?
Related
I've created an MVC application. I would like to now add a new class-library project to the solution, and then add an EDMX file to that project.
This used to be easy. But now I have to choose between .NET Core and .NET Standard. But it appears it doesn't matter which I choose because if I create a class library with either of these frameworks, Visual Studio provides no option for adding an EDMX file to them! And I don't see an option to add a standard .NET Frameworks class library.
So what is the secret incantation to add a new project to my MVC solution, and then add an EDMX file to that project?
Note: I do have the option of adding an EDMX file directly to the MVC project. But I would prefer to place it in a separate project, which I've done before.
EDMX file is deprecated with EF Core and I believe it has been removed from .net core projects as well.
If you need to do that, you may need to add it to a normal .net 4.5 project and copy the files but this will make no sense using it with .net core or .net standard.
You should be using Code First anyway as it is cleaner and easier to use.
If you already have the database, you can refer to this link, it can help you to scaffold the classes from the database
https://learn.microsoft.com/en-us/ef/core/get-started/aspnetcore/existing-db
#Jonathan: The EDMX file is old way of doing things. EDMX is nothing but a T4 template which facilitates in creation of edmx.
With .Net Core the best way is to:
1. Create a .net core library project. Add entityframeworkcore nuget package from here
2. The use this link, to generate your model's from DB
The concept of EDMX is not supported anymore.
Hope this helps.
Based on your description you're using the old ASP.NET MVC framework, and not the new Core one, and in this case you're using the Full .NET framework. So, when you create the new Class Library project, you should do it with the Full .NET Framework, because .NET Core and .NET Standard does not support, EDMX. If you chose this one, you can add your ADO.NET Entity Data model to it:
At least for EF v6, if your using EF Migrations, each ('state'/'target') snapshot of the database (stored within the migrations-history db table & migration file) is an EDMX file just waiting to be decoded, saved to a file, and then loaded in VS (Visual Studio). ;)
It's a little in-depth (or at least challenging), but 'System.Data.Entity.Migrations.Edm.ModelCompressor' may present the clue.
Basically, you can extract the EDMX from one/the relevant migration. But I do agree that the Code-First approach should be used for the implementation, the EDMX is only a development-aid these days.
I am trying to use EF6.0 in Class Library Project .Net Framework 4.6.2 (Repository project) where the DBContext live next to the repository and the Entities have been created in different project(.NET framework 4.6.2) using Reverse Code First POCO,
The Repository will be called thru another (framework 4.6.2) Manager Project referenced inside ASPNET Core 2.0 SPA Project, where StructureMap used as IoC.
The first thing I faced was the issue of passing the connectionstring to the DBContext inside Repository Project, as I want to Register the services (DBContext,Repository) inside the Repository Project not from the ASPNET Core Startup.cs, the reason to that is to avoid exposing the DBContext to the frontend project, anyway I ended up hard-coding the connection string in Repo Project temporarily, "appreciate if there is another way!"
The main issue that I am facing with this design comes when the request send to collect the list of "Products", it reaches to the Repository Project where the Linq statement use _dbcontext.Product , then error message thrown
NotSupportedException: Unable to determine the provider name for provider factory of type 'System.Data.SqlClient.SqlClientFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.
The Entityframework is registered inside Repository project, but not inside ASPNET Core 2.0 Project as it will show Nuget conflict error when its installed in ASPNET Core 2.0.
also I tried to install "System.Data.SqlClient" from Nuget in ASPNET Core2.0 but the error still throwing.
Any Idea on how to use EF6.0 in .netframework 4.6.2 class library project referenced inside ASPNET Core 2.0 project.
The Microsoft article Get Started with ASP.NET Core and Entity Framework 6 has the steps necessary for using Entity Framework 6 from a ASP.NET Core project.
Regarding the NotSupportedException, I would refer to the related question System.NotSupportedException: Unable to determine the provider name for provider factory of type 'System.Data.SqlClient.SqlClientFactory'.
I ran into the same issue because I failed to change the Core .csproj file from <TargetFramework>netcoreapp2.2</TargetFramework> to <TargetFramework>net471</TargetFramework> (which the article told me to do, but for some reason I thought wasn't necessary in Core 2.2).
I provided more explanation and details in the posted explanation/answer to the question I referenced above.
We have a large C# EF Code First based code base. Recently one F# project was added. The project uses FSharp.Data.SqlClient (http://fsprojects.github.io/FSharp.Data.SqlClient/) type provider to connect to DB.
That created a huge problem: F# type provider needs DB (and all referenced structures) to exist before the whole project can be complied from scratch, but EF needs to compile the whole project before it can create / update the DB. Subsequently, the DB can no longer be created from scratch or even modified.
While not using type providers is, obviously, possible, it is not an appealing solution because it nullifies the whole purpose of type providers and requires writing code that's already done by them.
Does anyone has any ideas how to deal with that? Thanks a lot!
Expanding on my comment, assuming you have currently only 2 VS projects:
Your C# project that contains everything including the EF code
Your F# project that contains the code that uses the type provider
What you could do is turn in into a 3 project solution:
A new and small C# project that only does EF stuff (migrations, schema definition, classes declaration)
Your F# project that contains the code that uses the type provider
Your existing C# project that would not contain the ef classes and ef related things but that references both #1 and #2.
That way, you EF C# project can compile first then run the migrations. Then your F# project would compile fine. Finally your 3rd project (that contains the rest of the logic that depends on both the EF and F# projects) can compile successfully.
I am using entity framework with DB first approach. I have migrated from EF5 to EF6 successfully. In EF5, I was using pre generated views to improve startup performance. In EF6, it is not working. I have generated views using power tool. Power tool generated it successfully and I can build the application without any error.
But When I run it, getting following error:
The current model no longer matches the model used to pre-generate the mapping views, as indicated by the ViewsForBaseEntitySetsfc4437b421d2fd7f4d645bf31e3cb5b1b8374d9c77a07ef5f36c1cac0bfea31a.MappingHashValue property.
Pre-generated mapping views must be either regenerated using the current model or removed if mapping views generated at runtime should be used instead
I am not able to understand why there is difference between the hash value generated via power tool and generated by EF at run time. There is no change in the edmx file.
There are more than 290 entities in edmx.
Version of entity framework in 6.1.3.
Power tool is VSPowerTools-Beta4.
I am using visual studio 2013.
Code generation startegy of edmx is 'Legacy ObjectContext'.
Is it possible to use the new ASP.NET with Entity Framework 6 instead of Entity Framework v7?
I use the latest Visual Studio 2015 and could not add a Ado.Net Data Model but the Reference to EF6 was added.
Most existing packages, such as EF6, will not support asp.net Core 5; because of the significant differences, they need to be manually updated. If you're wanting to use EF6 you'll need to stick to asp.net 5 (not Core).
I've run into a series of issues running the EF6 package manager commands, such as Add-Migration, in VS2015 CTP6; I believe they're still working on updates. I was able to get them working in a .Net 4.5 library that is referenced by my .Net 5 libraries, but I've found that occasionally I have to uninstall and install EF6 again to get the package manager commands working.