type or namespace name does not exist in the namespace

Question

I have the code below in a .cs file and I am coming across the errors below, any help would be appreciated.

using System.Data.Entity;

namespace Assignment2.Models
{
    public class TicketBookingEntities : DbContext
    {
        public DbSet<Performance> Performances { get; set; }
        public DbSet<Production> Productions { get; set; }
    }
}

Errors:

Error   1   The type or namespace name 'Entity' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)
Error   2   The type or namespace name 'DbContext' could not be found (are you missing a using directive or an assembly reference?)
Error   3   The type or namespace name 'DbSet' could not be found (are you missing a using directive or an assembly reference?)
Error   4   The type or namespace name 'DbSet' could not be found (are you missing a using directive or an assembly reference?)

Answer 1

Make sure your project contains a reference to EntityFramework.dll.
See the topic To add a reference in Visual C# in this link if you don't know how to add a reference.