DBContext Configuration is generating a configuration error

Question

I'm trying to use this DbContext in a POST method to add a record.

The constructor of the controller with this method is as follows:

public CookieController(ILogger<CookieController> logger, ICookieRepository cookieRepository)
{
    _logger = logger;
    _cookieRepository = cookieRepository;
}

Here is the method:

[HttpPost(Name = "")]
public IEnumerable<Cookie> PostCookie([FromBody] Cookie data)
{
    DbContextOptions<ReactWithASPDbContext> options = new DbContextOptions<ReactWithASPDbContext>();

    ReactWithASPDbContext dbContext = new ReactWithASPDbContext(options);

    // ...
}

The DbContext class looks like this:

public class ReactWithASPDbContext : DbContext
{
    public ReactWithASPDbContext(DbContextOptions<ReactWithASPDbContext> options): 
        base(options) 
   { 
   }

   // ...
}

This is the Program.cs code:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddDbContext<ReactWithASPDbContext>(options => { 
    options.UseSqlServer(

builder.Configuration["ConnectionStrings:ReactWithASPDbContextConnection"]); });

var app = builder.Build();
DbInitializer.Seed(app);

This is the DbInitializer method, and it works:

public static void Seed(IApplicationBuilder applicationBuilder)
{
    ReactWithASPDbContext context = 
         applicationBuilder.ApplicationServices
                           .CreateScope()
                           .ServiceProvider
                           .GetRequiredService<ReactWithASPDbContext>();

    // ...
}

The appsettings.json has this content:

"ConnectionStrings": {
   "ReactWithASPDbContextConnection": "Server= 

(localdb)\mssqllocaldb;Database=ReactWithASP;Trusted_Connection=True;MultipleActiveResultSets=True" }

But the configuration is generating this error:

No database provider has been configured for this DbContext. A provider can be configured by overriding the 'DbContext.OnConfiguring' method or by using 'AddDbContext' on the application service provider. If 'AddDbContext' is used, then also ensure that your DbContext type accepts a DbContextOptions object in its constructor and passes it to the base constructor for DbContext.

I'm assuming that I do not need to recreate the init stuff in the Program.cs file that creates an IApplicationBuilder etc. There should be a way to pass along the context once its created right?

Answer 1

It tells you that you have not added something like this

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    optionsBuilder.UseSqlServer(_connectionString);
}

as in

public class SomeContext: DbContext
{

    private readonly string _connectionString;

    public SomeContext(string connString) : base()
    {
        _connectionString= connString;
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer(_connectionString);
    }

    // Add DB sets here

}