Migration Providers¶

Migration providers are responsible for supplying migrations from various sources to the migration engine. They implement the IMigrationsProvider interface, which defines a method to return a collection of migrations.

The purpose of a migration provider is to abstract the source of migrations, allowing the migration engine to apply them without needing to know their origin. This enables flexibility in how migrations are defined and retrieved, whether from code, scripts, or other sources.

Existed providers¶

CodeMigrationsProvider¶

The CodeMigrationsProvider is designed to handle migrations written in C#. Migrations are sourced from specified assemblies, allowing for a structured and organized approach to migration management.

Methods¶

FromAssembly

Use this method to set up an assembly for scanning migrations. This is useful when you want to include all migrations from a specific assembly.
```
var builder = new MigrationEngineBuilder(services)
    .UseCodeMigrations()
    .FromAssembly(assembly);
```
FromAssembly

Use this method to set up an assembly for scanning migrations with a specified type. This is beneficial when you want to filter migrations by a specific type within an assembly.
```
var builder = new MigrationEngineBuilder(services)
    .UseCodeMigrations()
    .FromAssembly<MyMigrationType>(assembly);
```

ScriptMigrationsProvider¶

The ScriptMigrationsProvider is designed to handle migrations using raw SQL scripts. This provider is ideal for straightforward SQL-based migrations and can scan directories or assemblies for script files, allowing for a flexible approach to migration management.

Methods¶

FromDirectory

Use this method to set up a directory for scanning migrations. This is useful when you want to include all script migrations from a specific directory.
```
var builder = new MigrationEngineBuilder(services)
    .UseScriptMigrations()
    .FromDirectory("/path/to/scripts");
```
FromAssembly

Use this method to set up an assembly where script migrations are embedded. This is beneficial when you want to include script migrations from embedded resources within an assembly.
```
var builder = new MigrationEngineBuilder(services)
    .UseScriptMigrations()
    .FromAssembly(assembly, "MyNamespace");
```

How to add custom provider¶

To add a custom migrations provider, use the UseCustomMigrationsProvider method of the MigrationEngineBuilder class. This method allows you to specify your own implementation of the IMigrationsProvider interface.

public MigrationEngineBuilder UseCustomMigrationsProvider(IMigrationsProvider provider)

provider: An instance of a class that implements the IMigrationsProvider interface.

This method adds the custom provider to the list of migrations providers used by the migration engine.