I am creating an application using Entity Framework code-first.
How can I create the database using this model? Is it possible to create the DDL scripts from a code-first approach just like the DDL scripts that can be generated from a model first approach?
Update : Generate a sql server script from Entity Framework code-first architecture
Using Entity Framework Code-First the application, when run, will create the database and tables that support your .Net model classes. Therefore using this approach you don't need DDL scripts as the work will be done for you by the application.
In Entity Framework there has been a lot of effort put into the Migrations tool to enable the deployment of db changes. This is detailed here:
Automatic Code First Migrations
Code First Migrations
This seems to offer the most effective way of deploying db changes to multiple target environments.
Code First is not particularly capable when it comes to local database deltas. If you are doing anything with OnModelCreating within your db context then this will require your database to be deleted then recreated by the code first application. This is required by code first to ensure that the code model and the persistence model are kept synchronised.
These are two good starter tutorials on MVC with an EF component.
Code-First Development with Entity Framework 4
Intro to ASP.NET MVC 3
Related
We made an app in C#; we used EF but have created the models using a database-first approach. We lost the database and need to recreate it in order to continue development; how do I use the model in my database-first C# app in order to automatically create the database in SQL Server (trying to avoid tedious database and table re-creation).
Thanks in advance,
Ronan
I have a new MVC website (Internet Application) created using VS 2013.
I come from a Database first background and would like to take this approach for this project.
The project from what i see already has Entity Framework installed but i don't see any Entity Data Model files most likely because the project is Code First by default.
How could i bring the Database First approach in this project (the tables are already created within the database)?
Adopt the "Code First to an Existing Database" workflow, which is really a database-first workflow.
That will allow you to add a generated DbContext that maps to your existing database, without introducing an .EDMX file and the old designer-based database-first workflow.
The old EDMX-based database-first workflow should not be used for new work if you can help it. There's a lot of obsolete design and complexity in the OSpace/CSpace/SSpace mapping that Code-First hides from you, and EF Core has eliminiated entirely. There's some functionality in EDMX that hasn't been replicated in code-first, but there are reasonable workarounds for most of it.
I've been searching for a way, it may or may not be supported yet, I guess I'm looking for a concrete answer.
What I've been looking for is the solution for the following requirements:
EFCore Code First Approach
With existing database table with significant amount of data already in place
Add a couple of columns to the said database table by updating my model
No migrations through PM Console, just using Context with Fluent Api at application start
No database recreation
The approach can be: Check a configuration file or some sort, compare it against the version in a version table in database to trigger the update
Project templates: Web Api 2, Uwp
If this is supported, is it advisable? If not, why? what are the disadvantages?
In my experience with the projects I was part of, either database first approach or code first but with database recreation.
The steps I have in mind are:
- Update the model
- Create migration objects
- Update config file for db version
- At application start, check the config version against version table
- If versions do not match call Update() or Migrate() or both, with Migration objects/types as parameters
This is quite opinion based, but here are my comments.
EFCore Code First Approach
Are you aware of limitations of EF Core? It's linq provider cannot do everything EF6 does. differences between EF and EF Core?
With existing database table with significant amount of data already in place
That's OK.
Add a couple of columns to the said database table by updating my model
This seems standard practice for EF (Core) apps.
No migrations through PM Console, just using Context with Fluent Api at application start
I don't recommend automatic db upgrades because of the risks of the migration done not when you want it. I'd call it accidental-updagrade-database.
No database recreation
I'm not sure what this means, but yes, EF (Core) can work without recreating a db.
The approach can be: Check a configuration file or some sort, compare it against the version in a version table in database to trigger the update
Project templates: Web Api 2, Uwp
The Uwp part seems irrelevant as I assume that all db access will be done via the api app.
I am new to Entity Framework. I have created an EF Model and successfully added some tables and relation. Then I Clicked Generate Database from Model and My DB has been updated. Then I renamed some columns and I don't know how to revert or apply the changes. And Update Model from database does not seems to work because the columns names are different yet.
I need to graphically sync DB with Model. I prefer the model data rather than db data.
Thanks in advance.
You might want to look into the Code-First approach of Entity Framework. Using that approach you'll define your model in your code, and when changing anything you can create a Migration which allows you to up- and down-grade the DB to a specific version from the package manager console (or just create the respective SQL scripts).
For more information on this subject please see this article on MSDN
Note that you can also reverse engineer the code first model from an existing database (see 3. Reverse Engineer Model in this MSDN article), and then enable migrations for that model (see Step 2: Enable Migrations in this MSDN article)
What I do when I make "updates" is do it on both sides manually, in db and then in model (by right click properties) if the change is small. If adding a "new" table I drag it over to model from db server connections panel.
The alternative I've seen others prefer to use in this cases is to stay away from Entity Framework and use Dapper where you pass queries to it and it handles the rest.
Dapper (Wins!) vs Entity Framework vs ADO.NET Performance Benchmarking
I have an existing database and I am operating on data inside it via a .NET C# application using ADO.NET currently. I am suggested to use Entity Framework model. However, I want to add some stored procedures and tables to the database and use them when the compiled application runs. Can I create entity-framework model for current database without these to-be-added stored procedures and tables and then add those during runtime when using the compiled application?
Is it possible with entity framework model? Can someone give me some pointers about how to do this? I am new to entity framework.