{"id":6755,"date":"2016-09-29T13:39:01","date_gmt":"2016-09-29T20:39:01","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/dotnet\/?p=6755"},"modified":"2021-09-30T11:50:41","modified_gmt":"2021-09-30T18:50:41","slug":"implementing-seeding-custom-conventions-and-interceptors-in-ef-core-1-0","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet\/implementing-seeding-custom-conventions-and-interceptors-in-ef-core-1-0\/","title":{"rendered":"Implementing Seeding, Custom Conventions and Interceptors in EF Core 1.0"},"content":{"rendered":"

This post was written by Alina Popa<\/strong>, a software engineer on the .NET team.<\/p>\n

Updated 10\/5\/2016:<\/strong> This post has been updated to use improved Entity Framework Core techniques which don\u2019t rely on internal APIs.<\/em><\/p>\n

Implementing Seeding, Custom Conventions and Interceptors in EF Core 1.0<\/h2>\n

Introduction<\/h2>\n

Entity Framework Core (EF Core) is a lightweight and extensible version of the Entity Framework (EF) data access technology which is cross-platform and supports multiple database providers. You can find a comparison of EF Core vs. EF6 under the Entity Framework documentation<\/a>.<\/p>\n

When moving an application from EF6 to EF Core, you may encounter features that existed in EF6 but either are not present or are not yet implemented in EF Core. For many of those features, however, you can implement equivalent functionality.<\/p>\n

Seeding<\/h2>\n

With EF6 you can seed a database with initial data by overriding one of the following Seed()<\/code> methods:<\/p>\n

    \n
  • DbMigrationsConfiguration<TContext>.Seed()<\/code><\/a><\/li>\n
  • DropCreateDatabaseIfModelChanges<TContext>.Seed()<\/code><\/a><\/li>\n
  • DropCreateDatabaseAlways<TContext>.Seed()<\/code><\/a><\/li>\n
  • CreateDatabaseIfNotExists<TContext>.Seed()<\/code><\/a><\/li>\n<\/ul>\n

    EF Core does not provide similar APIs, and database initializers also no longer exist in EF Core. To seed the database, you would put the database initialization code in the application startup. If you are using migrations, call context.Database.Migrate()<\/code>, otherwise use context.Database.EnsureCreated()\/EnsureDeleted()<\/code>.<\/p>\n

    The patterns for seeding the database are discussed in issue 3070<\/a> in the Entity Framework Core repository on GitHub. The recommended approach is to run the seeding code within a service scope in Startup.Configure()<\/code>:<\/p>\n