EF Core set connection string

.net c# entity-framework entity-framework-core


I have a database project that's used by other dotnet projects (azure function app and a web app). I want to use dotnet ef core cli to work with migrations, but I don't want to keep my connection string in-code (I want to my repo to be public).

Here's my current DbContext:

public ChadwickDbContext(DbContextOptions options): base(options) {}

When I run something like: dotnet ef migrations add InitialCreate

I get the error:

Unable to create an object of type 'ChadwickDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

This worked previously because I had the connection string hard coded like this:

public ChadwickDbContext(string connectionString = "<connection string>"): base(GetOptions(connectionString)) {}

Is there any way to set the connection string via the cli or include some sort of environment file like appsettings.json in a database-only project?

Scaffolding seems to be close to what I want, but that appears to be more of a way to generate your context and models (which is already done).

12/22/2019 11:32:46 PM

Popular Answer

Looks like the best way to do this is to setup your own json file and register it:


        public ChadwickDbContext(): base(GetOptions()) {}

        private static DbContextOptions GetOptions()

            var config = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();
            var connectionString = config["ConnectionStrings:DefaultConnection"];
            var options = new DbContextOptionsBuilder();
            return options.Options;


  "ConnectionStrings": {
    "DefaultConnection": "<Connection String>"
12/23/2019 12:18:15 AM

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