Different seed for development and production - entity-framework

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
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
}
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" },
);
}
}
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();
}
}