DbContext Constructor

[guinness]

When creating EF Core Model from database would be possible to add the following additional constructor to the DbContext when using Generate Code?

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public myContext(DbContextOptions<myContext> options) : base(options) { }

This is needed for when Dependency Injection is being used:

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services.AddDbContext<myContext>(options => options.UseMySql(Configuration.GetConnectionString("myConnection")));

I could also add it manually since it's a partial class, but it seems this would be a common need.

[Shalex]

Thank you for your suggestion. We will notify you when the new constructor is added.

[Shalex]

The new (6.0.157) build of Entity Developer includes an updated predefined EF Core template (constructor added).

[guinness]

@Shalex - thanks, I confirm this is working in 6.1.265 version.

Is there anyway to remove the OnConfiguring method from the context? I have no need for it and would rather not have the connection string (including credentials) stored in our source control system.

[Shalex]

Please navigate to Model Settings, select "Use the following connection string from App.config" and clear selection of "Rewrite connection string during regeneration". After connection string is generated in app.config first time, delete it. Now no connection string will be created when saving the model and OnConfiguring will look like:

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        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseOracle(GetConnectionString("MyModelConnectionString"));
            CustomizeConfiguration(ref optionsBuilder);
            base.OnConfiguring(optionsBuilder);
        }

Otherwise, please modify a predefined template to remove OnConfiguring from generation. In this case you should call optionsBuilder.UseOracle manually.

[guinness]

Thanks, I took the former option. The latter seemed less attractive as I would have to update template in each subsequent application upgrade.

Note: You must also uncheck "Allow saving password" option in Connection properties dialog, otherwise the password will be stored in the .edps file which may be added to source control.

[guinness]

Please note that the following code in the EF Core template will not compile if using netstandard1.x framework:

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private static string GetConnectionString(string connectionStringName)
{
    System.Configuration.ConnectionStringSettings connectionStringSettings = System.Configuration.ConfigurationManager.ConnectionStrings[connectionStringName];
    if (connectionStringSettings == null)
        throw new InvalidOperationException("Connection string \"" + connectionStringName +"\" could not be found in the configuration file.");
    return connectionStringSettings.ConnectionString;
}

The reason is that System.Configuration is only available in the full framework. The new way would be to add

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services.AddSingleton<IConfiguration>(Configuration)

into Startup.cs and then inject IConfiguration into the DbContext then using

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config.GetConnectionString(connectionStringName)

in the GetConnectionString method.

[Shalex]

Thank you for your report. We will notify you when the issue is fixed.

[Shalex]

The bug with generating .NET Core code by EF Core template for the "Use the following connection string from App.config" option in Model Settings is fixed: viewtopic.php?f=32&t=35583.

JIC:
1. The package "Microsoft.Extensions.Configuration.Json" should be installed manually.
2. If necessary, turn on the "Rewrite connection string" option in Model Settings.