Hi I'm new to Entity Framework so excuse me if this question seem simple, but I have tried to find an example or question where this is described.
I have built a webApi interface with classes in what I call an eventmodell. The Interface and model is working well to receive stuff. But now I would like to build the CRUD functions to the database with Entity Framework.
I have added an empty code first model, but then I don't now how to generate csdl, msl and ssl files needed to create the database.
I have added Empty EF designer model but have found no way of adding an existing class to the designer.
I have installed EF Power Tools but that didn't help.
You seem to have a misunderstanding on how Code First works as compared to Database First.
There is no designer needed in a Code First approach. You add classes to your model, setup a DbContext and use Migrations to setup, and then at later stages, alter the database structure.
Checkout this tutorial: Getting Started with Entity Framework 6 Code First using MVC 5
Related
My team has inherited a database application that contains hundreds of tables. The application uses Entity Framework and takes a database first approach for development. Our current process is to pull a table or two at a time into the edmx using the Update Model From Database... tool.
We are considering making a new API with .Net Core, but as far as I can tell from the research I have done, there is no equivalent process in the Entity Framework Core tools. The closest thing I can find is to reverse engineer the entire database with Scaffold-DbContext, and then use migrations for all future database changes. We can't scaffold the entire database, because some of the tables have errors, and fixing all those errors is not a viable option for us right now.
I have found that I can supply a list of tables that I want scaffolded with the initial Scaffold-DbContext call, but I'm not sure if migrations can be used in a similar way to the Update Model From Database... tool. Can I use migrations to add tables that already exist in our database? If not, what other options should I be looking at?
In my recent interview, my interviewer we asked about approaches in entity Framework I told them code first and table first. Is there any approaches pending.
We can use three type of entity framework approach as per project requirement.
Database First:
An existing database can be used
Code can be auto-generated.
Extensible using partial classes/ T4 templates
The developer can update the database manually
There is a very good designer, which sync with the underlining database
http://www.entityframeworktutorial.net/database-first-with-entity-framework.aspx
Code First:
There is full control of the model from the Code; no EDMX/designer
No manual intervention to DB is required
The database is used for data only
http://www.entityframeworktutorial.net/code-first/what-is-code-first.aspx
Model First:
Good support with EDMX designer
We can visually create the database model
EF generates the Code and database script
Extensible through partial classes
I've currently got an ASP.NET MVC project, with three C# Class Libraries for Data Access, Settings and an Entity Framework Code First project.
I am currently trying to add a SQL Database Project to my solution so that I can manage my database more closely and add extra items that entity framework doesn't deal with.
I have searched around for integration options and can't find anything more helpful than going the DB first route and updating an edmx model from that.
How would I go about integrating my code first entity framework project with my SQL database project in a way that lets me edit the tables with code first and manage stored procedures and the rest with the database project.
If this is possible, is there any particular way to get these to deploy without conflicting?
Thanks!
I'm working on a project using entity framework 6. At the start of the project I was a beginner with EF and choose to build with EF model first.
Now the model is quite big and I’m thinking about performance and ease to change the model without dropping the databases every time.
I thinking about switching to code first.
Given that model first has already generated all the classes I need and context, I don't think it's that difficult to switch to code first.
Nevertheless I would like to know what would be the best way to do that and if there will be real advantage in term of performance and ease of model modification.
Thanks for your help,
EF 6.1 tooling now allows creating a Code First model from the database. Here is a short video and a walkthrough showing the functionality. You can download the latest EF tooling from the download center.
The code created by EDMX is not same as Fluent API although it is closed to Data Annotations.
If you would like to work with Fluent API, you can use Entity Framework Power Tools Beta 4 to generate to Fluent API from Database.
I'm using the latest EntityFramework 5 from NuGet. I don't know if I'm doing wrong, but it seems that complex types don't work with this template! (???) No matter what I do, I always get this compile-time error:
Running transformation: System.InvalidCastException: Unable to cast object of type 'System.Data.Metadata.Edm.ComplexType' to type 'System.Data.Metadata.Edm.PrimitiveType'.
For example:
I created an empty model "SimpleModel", then I added a simple entity in it, "Foo" and a complex property called "Something" of complex type "Bundle". Did all this using the EDM designer.
I went to "Generate Database from Model" so as to persist the model in a SQLEXPRESS DB. Ran the script and everything went OK. I tested writing some stuff using the new entity model and it worked fine, i.e., SaveChanges() worked OK.
I went to "Add Code Generation Item" and selected this template: EF 5.x DbContext Fluent Generator to create the "SimpleModel.tt" series of template files and I immediately got the error above.
When looking at the "SimpleModel.Mapping.cs" file generated by the "SimpleModel.Mapping.tt" template, I see that this code file is incomplete. This is the the only file incomplete, i.e., the generation of mapping code is breaking. Is this template compatible with the latest EF 5?
I have an existing DB with several tables and an entity model in place based on ObjectContext and EntityObjects (i.e, Model-First stuff). Most importantly, I have an existing data layer that makes use of entities mapped to these tables and lots of the data is rather appropriately bundled in complex types (bundled numeric and text stuff with no identity).
The point is that I need to migrate my entity model from using ObjectContext and EntityObjects to DbContext and POCOs, then I want to go Code-First. How should I do this?
Any help is appreciated beforehand!
How should I do this?
Imho either use EF Power tools (but I think they don't support EF 5 yet) and reverse engineer database or write code first mapping yourselves.
That generator is not provided by MS and if you have any problem with it you should report it to its developer as a bug. If you check Q/A for this generator in Visual Studio Gallery it claims that complex types are not supported.