Different seed for development and production

Question

What is the recommended approach to seed a database differently using Entity Framework (6+) depending on the build configuration (Debug / Release)?

Right now I am using the MigrateDatabaseToLatestVersion initializer. During development I like to have fake data in my database for testing. So I create this test data in the Seed method of the Configuration class (that came with enabling code-first). However, each time I publish the product via build server I have to comment a lot of code inside my seed method, commit this, create the release, and then undo all the comments to continue development with the test data.

I guess this is not the way to go. So I hope you can tell me the proper way to do it.

Answer 1

there are many possibilities

1. Preprocessor directive

One is like you and Gert Arnold already talked about, using the #if DEBUG:

protected override void Seed(BookService.Models.BookServiceContext context)
{
#if DEBUG
    context.Authors.AddOrUpdate(x => x.Id,
        new Author() { Id = 1, Name = "Test User" },
    );
#else
    context.Authors.AddOrUpdate(x => x.Id,
        new Author() { Id = 1, Name = "Productive User" },
    );
#endif
}

2. Configuration

Another way would be with configuration in the appsettings.json, maybe you want to set up the application with development-data, you can add something like

{ "environment" : "development" }

and in the seed you check for this:

protected override void Seed(BookService.Models.BookServiceContext context)
{
    var builder = new ConfigurationBuilder();
    builder.AddInMemoryCollection();
    var config = builder.Build();

    if (config["environment"].Equals("development"))
    {
        context.Authors.AddOrUpdate(x => x.Id,
            new Author() { Id = 1, Name = "Test User" },
        );
    }
    else if (config["environment"].Equals("producion"))
    {
        context.Authors.AddOrUpdate(x => x.Id,
            new Author() { Id = 1, Name = "Productive User" },
        );
    }
}

3. Environment variables (solution for asp net core)

(see also https://docs.asp.net/en/latest/fundamentals/environments.html)

You can add an environment variable

and later on via DI:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        SeedDataForDevelopment();
    }
}