DbContextFactory InvalidOperationException in Blazor App

Question

I’ve changed my use of DbContext to incorporating DbContextFactory in order to handle multiple sql transactions. I’ve run into a couple questions/errors trying to do this.

1. I have 3 different tables in my database that are accessed for different functions so I created 3 different services to handle them. Is this correct? Is there a better way? I'm not sure this if this is related to the problem but I want to make sure I'm not adding unnecessary complications.

   My tables: Category, Expense, Items My services: CategoryService, ExpenseService, ItemService Each service has a GetAll, GetbyKey, Update, and Delete.

2. After adding the DbContextFactory to my services, I’m getting an error I don’t understand. Here’s part of my Program.cs code:

builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddDbContextFactory<BudgetDBContext>(options => options.UseSqlServer("DefaultConnection")); 
builder.Services.AddScoped<ExpenseService>();
builder.Services.AddScoped<CategoryService>();
builder.Services.AddScoped<ItemService>();
builder.Services.AddDbContext<BudgetDBContext>(item => item.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));
var app = builder.Build();

Here’s the part of my page code:

    private async void GetCategories()
{
    categories = await categoryService.GetAllCategories();
    GetUICategories(categories, uiCategories, uiSubCategories);
}

Here’s the part of my CategoryService code:

        public async Task<List<Category>> GetAllCategories()
    {
        using var dbContext = _factory.CreateDbContext();
        return await dbContext.Categories.ToListAsync();
    }

Here’s the error that’s happening at return await dbContext.Categories.ToListAsync(); in the CategoryService:

System.InvalidOperationException: 'Instance failure.'

I think I must have added the DbContextFactory incorrectly in the Progam file but I'm not sure that's what the problem is.

Update: I meant to post the following for the AddDbContextFactory line.

builder.Services.AddDbContextFactory<BudgetDBContext>(options => options.UseSqlServer(@"Server=DESKTOP-JMIKVDI\\SQLEXPRESS;Database=BudgetDB;Trusted_Connection=True;TrustServerCertificate=True"));    

Using DefaultConnection as AddDbContext does changes the error.

builder.Services.AddDbContextFactory<BudgetDBContext>(options => options.UseSqlServer("DefaultConnection"));