How do I code my first migration?

How do you code first migration?

The actual concept of Code First Migration is as follows.

1. Make some more changes to our model. …
2. Run the application. …
3. Now it’s time to use the Code First Migration approach.
4. Open Package Manager Console.
5. Run Enable-Migrations command in a Package Manager console.

What is migration in code?

Migration in EF 6 Code-First

These strategies used to drop the entire database and recreate it, so you would lose the data and other DB objects. Entity Framework introduced a migration tool that automatically updates the database schema when your model changes without losing any existing data or other database objects.

How do you drop a table in code first migration?

To remove a table, simply remove the corresponding DbSet<MyClass> and any references to that class in other parts of your model and EF will add a DropTable to the migration automatically. If you are no longer using the class for non-Entity Framework purposes you can delete it.

How do I add a code to Visual Studio migration?

Open the Package Manager Console from the menu Tools -> NuGet Package Manager -> Package Manager Console in Visual Studio and execute the following command to add a migration.
…
Adding a Migration

1. <timestamp>_<Migration Name>. …
2. <timestamp>_<Migration Name>. …
3. <contextclassname>ModelSnapshot.

What is the code first approach?

Code-First is mainly useful in Domain Driven Design. In the Code-First approach, you focus on the domain of your application and start creating classes for your domain entity rather than design your database first and then create the classes which match your database design.

What is DbContext C#?

DbContext is an important class in Entity Framework API. It is a bridge between your domain or entity classes and the database. DbContext is the primary class that is responsible for interacting with the database. … Querying: Converts LINQ-to-Entities queries to SQL query and sends them to the database.

What are 4 types of migration?

1. Build background about human migration and types of migration.

• internal migration: moving within a state, country, or continent.
• external migration: moving to a different state, country, or continent.
• emigration: leaving one country to move to another.
• immigration: moving into a new country.

What is scaffold DbContext?

Reverse engineering is the process of scaffolding entity type classes and a DbContext class based on a database schema. It can be performed using the Scaffold-DbContext command of the EF Core Package Manager Console (PMC) tools or the dotnet ef dbcontext scaffold command of the . NET Command-line Interface (CLI) tools.

How do I migrate a database?

In order to migrate the database, there are two steps:

1. Step One—Perform a MySQL Dump. Before transferring the database file to the new VPS, we first need to back it up on the original virtual server by using the mysqldump command. …
2. Step Two—Copy the Database. SCP helps you copy the database. …
3. Step Three—Import the Database.

How do I get rid of last migration?

Removing and Resetting Migrations

1. Remove the _MigrationHistory table from the Database.
2. Remove the individual migration files in your project’s Migrations folder.
3. Enable-Migrations in Package Manager Console.
4. Add-migration Initial in PMC.
5. Comment out the code inside of the Up method in the Initial Migration.

How do I get rid of add-migration?

7 Answers. If you haven’t used Update-Database you can just delete the migration file. If you’ve run the update you should roll it back using Update-Database -TargetMigration “NameOfPreviousMigration” then delete the migration file.

How do you reverse migration?

You can use zero as your migration number to revert all migrations of an app. The other thing that you can do is delete the table created manually. Along with that, you will have to delete that particular migration file.

Which command is used to run migration?

EF Migrations series

Enable-Migrations: Enables Code First Migrations in a project. Add-Migration: Scaffolds a migration script for any pending model changes. Update-Database: Applies any pending migrations to the database. Get-Migrations: Displays the migrations that have been applied to the target database.

How do you update-database code first?

Update an Existing Database using Code First Migrations with ASP.NET and Entity Framework

1. Enable-Migrations -ContextTypeName CodeFirstExistingDB.StoreContext.
2. Add-Migration InitialCreate -IgnoreChanges.
3. namespace CodeFirstExistingDB. { …
4. Add-Migration add_product_description.
5. namespace CodeFirstExistingDB.Migrations. {

How do you add a column in code first approach?

Run Two Commands, That’s It

1. Remove-Migration.
2. Once you run the add-migration command, a new migration class will be created and opened, in that, you can see a new column has been added to the Employee table. …
3. Once add migration is done, the next step is to update the database with the new changes. …
4. Update-Database.