/pluralsight-efcore-getting-started

Primary LanguageC#

Entity Framework Core: Getting Started

This is based on the Pluralsight course, Entity Framework Core: Getting Started, but modified slightly to work more nicely with .NET 6 and in IDE/editors other than Visual Studio, in particular VS Code.

Rather than attaching a database to the project directly, which would be relatively normal in Visual Studio, this connects to a local MS SQL/Postgres server which is handled by Docker via Docker Compose (see notes).

Requirements

  • .NET 6.0 SDK
  • The Entity Framework tool should be installed globall for .NET with dotnet tool install --global dotnet-ef
  • Docker (configured to be able to run Linux containers)

Getting Started

For managing the database, there are a few commands which are useful to have to hand:

  • To start up the database server the first time and watch the logs: 
    docker compose up
  • To start up the database server the first time and not watch the logs: 
    docker compose up -d
  • After the database server has been started once, but is currently stopped and you want to restart it: 
    docker compose start
  • If the database server is currently running and you want to stop it: 
    docker compose stop
  • If you want to tear down the database server (i.e. stop it if it's running and remove it entirely): 
    docker compose down

Using dotnet commands instead of the Package Manager Console

As we're not using Visual Studio, it makes sense to use the dotnet CLI instead of the Package Manager Console to handle Entity Framework commands. Here are a few examples of how that changes:

Package Manager Console dotnet Description
add-migration <name> dotnet ef migrations add <name> Creates a new migration in Entity Framework
update-database dotnet ef database update Runs all migrations which have not been executed against the database
get-migration dotnet ef migrations list List all migrations and their status

You can view more of these commands with the dotnet ef command.

Notes

  • There is a .env file in the root directory which contains the environment variables for the MS SQL Server, this may not normally be under source control as it contains secrets (or it may be one of many environment variables files, of which one or more may not be under source control for similar reasons).
  • Currently, the connection string is hardcoded in the SamuraiApp.Data project, in the SamuraiContext.cs file, as per the course. This contains the password from the .env file again, so if you want to change the password for your MS SQL Server, you will need to change this in both places. This is also the case for the port, if you want to change that. Ideally, this would be generated based on the environment variables, but as this is a training course this is not necessary at this point.
  • These projects are set up to have the nullable enabled, and that means that by default any classes are not nullable unless otherwise specified. this was not fully supported in EF Core 5, but it is in EF Core 6, so when it comes to added dependent tables in a one-to-one setup, be sure to add the property as a nullable instead the default.
  • I've moved this over to use Postgres as of 2022-04-13, the original MS SQL Server container is still in the docker-compose.yml, however this is now commented out and the migrations were recreated to work with this
    • If you want to switch database server, it is best to remove all of the existing migrations and snapshot and then run dotnet ef migrations add init to create a new init migration for the new database server