Aspnetcore.docs: We could use EnsureCreatedAsync using async Main

[weitzhandler]

In .NET Core > 2.1, async Task Main can be used instead, then EnsureCreatedAsync could be used.

I find it really important to point that out in the docs, because many people are looking for ways to initialize post-build app stuff, that are many times asynchronous.

Here's an example question in SO.

Created PR #17750.

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Document Details

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• ID: 7a54c97f-ddd4-b041-5e5f-a2df009ace50
• Version Independent ID: fa488196-1f98-08ea-adcc-17d9dac86727
• Content: Razor Pages with Entity Framework Core in ASP.NET Core - Tutorial 1 of 8
• Content Source: aspnetcore/data/ef-rp/intro.md
• Product: aspnet-core
• Technology: aspnetcore-data
• GitHub Login: @Rick-Anderson
• Microsoft Alias: riande

[Rick-Anderson]

EnsureCreatedAsync is not suitable for production apps.

[weitzhandler]

Can you please explain why?

[Rick-Anderson]

@ajcvickers please review. We should probably update the doc's with best practice.

[ajcvickers]

@Rick-Anderson @weitzhandler As part of the plan for EF Core 5, we are investigating better experiences for migrating the database that don't involve running migrations from code--see https://github.com/dotnet/efcore/issues/19587. This will likely result in something like "migration bundles" that can easily be deployed at the same time as the database. We also have https://github.com/dotnet/efcore/issues/20402 which is about integrating this into something like the ASP.NET Core error page middleware.

With regard to the associated PR, the async change is probably marginally better than what we have now, but we need to revisit this after we have got further along the bundles path.

/cc @JeremyLikness @bricelam

[bricelam]

Async doesn't really help in this situation. The application isn't accepting requests at this point. There is effectively only one thread running and yielding it will probably only make it take longer to start up and begin accepting requests.