The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)

When I made changes to the web.config file of an ASP.Net C# application, I have accidentally deleted a comma, and I started to get the runtime error message: The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047) Make sure all necessary commas are there in the config files, Visual Studio does not […]

Connect to a MySQL database from Visual Studio 2017

As of today weI can connect to a MySQL database, but cannot generate the Entity Data Model from a MySQL database in Visual Studio 2017 To access a MySQL database from Visual Studio 2017 IMPORTANT: First install MySQL for Visual Studio, and after that install MySQL Connector/Net. If MySQL Connector/Net is already installed on your workstation, uninstall […]

Generate Entity Framework Entity Data Model in Visual Studio 2017

Visual Studio 2017 has many project type options, and not all of them support the Entity Framework user interface to generate the Entity Framework Data Model (EDMX) file. If you create an ASP.NET Web Application(.NET Framework) you can add the EDMX file to it. The .NET Core projects do not support the Entity Framework Data Model […]

{“error”:”Entity type ‘AspNetUserRoles’ has composite primary key defined with data annotations. To set composite primary key, use fluent API.”}

When a database table has composite keys (multiple columns are in the key) you cannot use the usual key definition [Key] [Display(Name = “UserId”)] public string UserId { get; set; } [Key] [Display(Name = “RoleId”)] public string RoleId { get; set; } When you run the application you get the error message: {“error”:”Entity type ‘AspNetUserRoles’ has composite […]