When I create Entities within the Graphical view of the edmx file. All my entity classes are bundled together in the Designer file. Is there a way to make Entity Framework to create classes in separate files allowing me to have more control over my entity classes?
If you are using Visual Studio 2010, click on the design surface of the EDM Designer and select Add Code Generation Item, then select ADO.NET POCO Entity Generator. This will create a T4 Template file (*.tt) that will be used to generate your POCO classes. Every class will have it's own file.
You have to be aware of the fact that every time you make changes to your EDM and save, those classes will be re-generated and the files will be re-written, so it's better not to make any changes to them directly. Those classes are partial, so you can create new files and build up your classes without changing the initial files.
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Before I used EF4 to generate my entity data model from an existing database. I can do CRUD operations on every generated entity, because the entities context class with all the methods is automatically generated. Now I have upgraded my project to EF6, deleted the files created by the EF4 data model wizard and generated it again using EF6 data model wizard. Now I get a T4 template file with a context class below it, a T4 template file with for every entity a class with code, a empty designer file and an edmx diagram file. But there are no methods such as AddObject, DeleteObject, SaveChanges generated. How can they be generated as it did before with EF4?
EF6 should still generate a context for you. It provides the mentioned methods. Are you sure you just missed in amongs all the .tt files?
EDIT: Also, make sure you have all the proper references to EF. There might be a compiler warning indicating a problem.
I am using VS 2012 and EF 5. I have an existing database that I want to create POCO classes from the existing database. I followed the steps to add an ADO.NET Entity Data Model to my project. I went through the wizard to use an existing database. It then created the edmx and tt files with the designer open. However, I want to create the POCO objects and use them. The Microsoft site states that the POCO Entity Framework Generator is obsolete and I should use the DBContext Generator. I can't figure out steps I use to generate the POCO classes. I only see the edmx designer. I really don't even want an edmx file but instead just POCO classes. How can I get POCO classes to be created from an existing database using EF 5 and VS 2012?
Use EF 5.x DbContext Fluent Generator
You can add it from online templates:
Generate edmx from existing database
Select Add New Item
Search online templates for POCO
Add EF 5.x DbContext Fluent Generator
It will add three T4 templates to your project:
XXX.Context.tt - context inherited from DbContext
XXX.Entities.tt - POCO entities
XXX.Mappings.tt - fluent mappings for each entity
BUT you need to setup path to your edmx data model manually. Each of these templates have line string inputFile = #"$edmxInputFile$";. You need to provide name of your edmx file here:
string inputFile = #"Northwind.edmx";
The process to do this is pretty streamlined now, it seems. The steps from the accepted answer are now easy to do from the EDMX designer itself. Basically,
Generate the model (edmx) from an existing database by adding ADO.NET Entity Data Model to the project (see here for more details),
and then
Open the .edmx file in the Entity Designer.
Right-click an empty area on the Entity Designer surface and point to Add Code Generation Item.
In the Add New Item dialog, select Online Templates and type DBContext in the Search Online Templates text box.
Select the appropriate version for your template (5.0, if you want to target the Entity Framework 5.0).
Click OK.
This will do all the work, apparently. The quoted instructions here refer to Online Templates as installing EF 5.x DbContext Fluent Generator is required. If you have it already installed, there is no need to search for it in the Online Templates but in the Installed Templates.
For more info you can check this page, section "To use the DbContext Generator Template to Generate Object Layer Code".
Okay, I feel a bit foolish for having to ask this but I guess my understanding of the inner workings of Entity Framework is lacking.
I'd like to experiment with work with DbContext. I have an existing ASP.NET MVC application using EF 4.2. I can get my entities using:
var context = new MyEntities();
And this works just fine.
But how the heck to I get the same data represented by a DbContext?
So I guess you are using default code generator provided by EDMX designer - it will use ObjectContext and heavy weight EntityObject based entities.
If you want to use DbContext you must:
Turn off that default code generation - in property window remove Custom Tool for EDMX file
Download and install DbContext T4 generator (you can get it directly from extension manager in Visual Studio)
In EF designer select Add Code Generation Item from context menu in the designer surface (not on entity)
Now EF will add two .tt files to your project - one will be responsible for creating a new class for every entity or complex type defined in your EDMX file and the second will be responsible for creating class derived from DbContext and exposing sets for all your entity types
Maybe my google fu is sucking but I can't find any tutorial on how to use Entity framework without using the designer in Visual Studio. Is there a way to use Entity framework without the designer?
You can either use code first approach (it requires EFv4.1 or newer) where the mapping is defined in code (or by default mapping conventions) or you can create EDMX file from scratch - it is XML file.
They are two ways:
Classical (database first): You can learn about xml EF files on msdn .edmx File Overview (Entity Framework)
An .edmx file is an XML file that defines a conceptual model, a
storage model, and the mapping between these models. An .edmx file
also contains information that is used by the ADO.NET Entity Data
Model Designer (Entity Designer) to render a model graphically.
New (code first): They are a lot of resources. Here a MS code first video.
so far i was creating a classLibrary project and inserting new Ado.net Entity data model and genareting from exixting database. Class and object class codes are creating automatically.
this is not important for me.
but i want to do this and separate the ObjectContext class (ex: SomeEntities) and table classess to two calss library.
when i change the database tables property, i will update edmx model and classes will update automatically.
is there any way to do this?
i am not using codefirst because have a database and datas in it,
i am not using modelfirst likewise,
i am using databasefirst but can not separate
Since you have "poco" in your title I guess that you are using the EF4 POCO Generator T4 Template.
Then yes, you can separate POCO classes and ObjectContext into two different class libraries. The T4 Template is prepared for that scenario since it consists of two different files:
POCOGenerator.Context.tt -> responsible to create your derived ObjectContext
POCOGenerator.tt -> responsible to create your POCO entities
If you add the POCO generator in the class library where you have your EDMX file, by default both tt-files will be added there.
But you can move then the second file (POCOGenerator.tt) into another class library. (The EDMX project where the context is located needs to reference this library to recognize the POCO classes.) After that open this file in a text editor. Some of the first lines in this file will look like:
...
string inputFile = #"MyModel.edmx";
EdmItemCollection ItemCollection = loader.CreateEdmItemCollection(inputFile);
...
You now need to change the path to the edmx file (only in POCOGenerator.tt, leave POCOGenerator.Context.tt unchanged). Assuming you have edmx project and POCO project in the same solution of Visual Studio, the new path might be:
...
string inputFile = #"..\..\MyEDMXProject\MyModel.edmx";
EdmItemCollection ItemCollection = loader.CreateEdmItemCollection(inputFile);
...
Now you can execute both files separately from two different projects. One will create the context file and the other will create your POCO files.