Change Model After Code First Migration - asp.net-mvc

Question

I enabled Code First Migration but after sometime I changed the model properties so when i ran the application the following error is given.
Invalid column name etc...because after migration i changed the model.
So far I understand the problem is that I updated the model but these changes don't apply to database table...kindly help me to fix it..means model properties and database column don't match
Migration is enabled.
I set automatic migration to true but i doesn't work.
Error
public class Floor
{
public int FloorID { get; set; }
public string Name { get; set; }
public virtual ICollection<Room> Rooms { get; set;}
}
public class Room
{
public int RoomID { get; set; }
public string Name { get; set; }
[Display(Name ="Room Rent")]
public decimal Rent { get; set; }
[Display(Name="Floor")]
public int FloorID { get; set; }
public int Seater { get; set; }
[Display(Name="Attach Bathroom")]
public Boolean AttachedBathRoom { get; set; }
public virtual Floor Floor { get; set; }
public virtual ICollection<Student> Students { get; set; }
}
public class Student
{
public int StudentID { get; set; }
public string Name { get; set; }
public int CNIC { get; set; }
public int Phone { get; set; }
[Display(Name="Floor")]
public int FloorID { get; set; }
[Display(Name ="Room No")]
public int RoomID { get; set; }
public string Address { get; set; }
public string Email { get; set; }
public string Department { get; set; }
public virtual Floor Floor { get; set; }
public virtual Room Room { get; set; }
}

Answer 1

First, you need to specify your primary and foreign keys in your classes.
To specify a primary key, add [Key] before your key attribute. For a foreign key, you also have to add the table it is linked to. So in your Room class you would have something like this:
[Key]
[ForeignKey("Floor")]
public int FloorID { get; set; }
Do the same for all your keys in all your models.
Then, you need to add a new migration and then update your database.
In your Packet Manager Console, type this to add a new migration:
Add-Migration FooBar
Then update your database with this command:
Update-Database