通过使用EntityFramework添加新记录

Question

I am creating a test project in order to learn using asp.net 5 and the mvc 6 framework.

I have decided to create a simple webpage that each menu item comes from the database. To do so I have created a model like such

namespace TestTemplate.Models
{
    public class SideMenuItem
    {
        public int Id { get; set; }

        public string Level { get; set; }

        public string Label { get; set; }

        public string Link { get; set; }
    }
}

Inside my Models folder I also have a file named `TestContext.cs'

namespace TestTemplate.Models
{
    public class TestContext : DbContext
    {
        public DbSet<SideMenuItem> SideMenuItems { get; set; }
    }
}

That is my EntityFramework DbContext class.

When trying to create a new SideMenu item by using a simple view with a form to adding all the needed data, then using my angular factory that looks like this

return $resource('/api/sidemenu/:id');

I get the error:

An exception of type 'Microsoft.Data.Entity.DbUpdateException' occurred in EntityFramework.Core.dll but was not handled in user code

Additional information: An error occurred while updating the entries. See the inner exception for details.

-->System.Data.SqlClient.SqlException: Invalid object name 'SideMenuItem'.

This error occurs on SideMenuController.cs where I define my API at the part where I am trying to Post the new item:

[HttpPost]
public IActionResult Post([FromBody]SideMenuItem sideMenuItem)
{
    if (sideMenuItem.Id == 0)
    {
        _dbContext.SideMenuItems.Add(sideMenuItem);
        _dbContext.SaveChanges();                        // ERROR HERE.
        return new ObjectResult(sideMenuItem);
    }
    else
    {
        var original = _dbContext.SideMenuItems.FirstOrDefault(m => m.Id == sideMenuItem.Id);
        original.Level = sideMenuItem.Level;
        original.Label = sideMenuItem.Label;
        original.Link = sideMenuItem.Link;
        _dbContext.SaveChanges();
        return new ObjectResult(original);
    }
}

I also should mention that before running the app i used

>dnx ef migration add initial
>dnx ef database update

I believe it has to do with me not creating my database correctly. Since I am not seeing any folder on my project that had anything to do with databases or migrations.

Why is it complaining that SideMenuItem is invalid, and how can I fix the issue?

Answer 1

After trying to create my database again, I noticed that I had a typo on my migration command, hence the database was not created.

The command should have been dnx ef migrations ... with an s.

A good starting point with all the commands can be found here .