craniodev / Sample-SplitMigrations

Use EFCore Migrations with multi-assembly project

How to use EFCore Migrations with layers

This sample show how to use EFCore Migrations when your application is split up into seperate assemblies or architectural layers.

The layers

This sample application is split into four assemblies.

Assembly	Description
MyApp.Data	Contains the DbContext
MyApp.Migrations	Contains migration classes and the model snapshot
MyApp.Models	Contains POCO entity type classes
MyApp.Web	The web app. Configures the DbContext

Running commands

To run the commands, MyApp.Migrations should be used as the target project (Default project or -Project in PMC, and --project in CLI), and MyApp.Web as the startup project (-StartupProject in PMC, and --startup-project in CLI).

cd ./MyApp.Migrations/
dotnet ef migrations add Migration2 --startup-project ../MyApp.Web/

Points of interest

There are a few parts of the sample that deserve some attention.

References

Look at the project and package references. Anywhere you see PrivateAssets="All", it means that that reference should be available during development, but shouldn't get published to the server.

Migrations assembly

In Startup.ConfigureServices(), we tell the DbContext where to find the migrations classes:

optionsBuilder.UseSqlServer(
    connectionString,
    x => x.MigrationsAssembly("MyApp.Migrations"));