How to Pass CreateDbContext Args Parameters? - entity-framework-core

Question

I have a multiple DBContexts and DesignTimeDbContextFactory implementation like below.
public class MasterDbContextFactory : IDesignTimeDbContextFactory<MasterDbContext>
{
public MasterDbContext CreateDbContext(string[] args)
{
StringBuilder sb = new StringBuilder();
foreach (var arg in args)
sb.AppendLine(arg);
System.IO.File.WriteAllText("D:\\debug.txt", sb.ToString());
string server = args[1];
string databaseName = args[2];
string connectionString = string.Format(Constant.Connection, server, databaseName);
var optionsBuilder = new DbContextOptionsBuilder<MasterDbContext>();
optionsBuilder.UseSqlServer("connection string");
return new MasterDbContext(optionsBuilder.Options);
}
}
As mentioned here, I apply like this.
Update-Database -Context MasterDbContext -AppArgs 'LAPTOP-E4UBP70J' 'MASTER_USER'
But I don't see all args parameters.

Answer 1

The feature is only available in recent release EF Core 5.0 Preview 6
Flow arguments into IDesignTimeDbContextFactory
Arguments are now flowed from the command line into the CreateDbContext method of IDesignTimeDbContextFactory. For example, to indicate this is a dev build, a custom argument (e.g. dev) can be passed on the command line:
dotnet ef migrations add two --verbose --dev

Answer 2

This work well at 5.0.0-preview.7.20365.15 version.
Adding migration with additional args:
Add-Migration InitialCreate -Context MasterDbContext -OutputDir Migrations\Master -Args 'P1 P2'
Updating migration with additional args:
Update-Database -Context MasterDbContext -Args 'P1 P2'
Here is source

Answer 3

Using Entity Framework Core .NET Command-line Tools version 5.0.7 or newer you can pass custom 'application arguments' into the CreateDbContext method by appending -- to the end of the command, followed by a space and then your arguments.
e.g. dotnet ef database update --context MyContext -- MyFirstArg MySecondArg
See
https://github.com/dotnet/efcore/issues/8332#issuecomment-644918706 which describes how to pass arguments when using both Command-Line and Powershell commands.
Command-Line
The commands will no longer interpret any extraneous arguments as application arguments. Instead, if you want to call a dotnet ef command with application arguments, you must now put -- after you pass in all the normal arguments, followed by whatever you want to the application arguments to be. All arguments after the -- will be interpreted as application arguments. If you need to pass in an application argument which, for instance, contains a space you will need to quote that argument e.g.
dotnet ef migrations add InitialCreate -- FirstAppArg "This is all the second application argument" ThirdAppArg