Entity framework conventions - entity-framework

Question

I have just started to work with the Entity framework and have created my Repository and context class and interfaces and defined my POCO and I am now trying to understand how the conventions working but am having difficulties and thus far have been unable to do so.
I have the following 2 POCO classes:
Gameweek
public class Gameweek
{
[Key][Required]
public int GameweekID { get; set; }
[Required]
public DateTime StartDate { get; set; }
[Required]
public DateTime Deadline { get; set; }
[Required]
public int NumberFixtures { get; set; }
public virtual ICollection<Fixture> Fixtures { get; set; }
public virtual ICollection<Result> Results { get; set; }
}
Fixture
public class Fixture
{
[Key][Required]
public int FixtureID { get; set; }
[Required]
public int GameweekID { get; set; }
[Required]
public string HomeTeam { get; set; }
[Required]
public string AwayTeam { get; set; }
public virtual Result Result { get; set; }
}
Result
public class Result
{
[Key][Required]
public int FixtureID { get; set; }
[Required]
public int HomeGoals { get; set; }
[Required]
public int AwayGoals { get; set; }
}
In my model a Gameweek could contain between 0-20 fixtures. Each fixture in the gameweek has one result.
Am I modelling this correctly with the classes and the following convetions:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove < PluralizingTableNameConvention>();
//Table relationships defined here
modelBuilder.Entity<Gameweek>()
.HasMany(g => g.Fixtures);
modelBuilder.Entity<Fixture>()
.HasOptional(f => f.Result);
}
Any tips would be greatly appreciated.

Answer 1

Apparently you want to have a one-to-one relationship between Fixture and Result (a Result entity cannot be shared between multiple Fixtures), right? In this case your mapping is not 100% correct. You need:
modelBuilder.Entity<Fixture>()
.HasOptional(f => f.Result)
.WithRequired();
If you don't add WithRequired EF conventions will assume a WithMany, i.e. a one-to-many instead of one-to-one relationship.
Speaking of conventions, you can actually remove modelBuilder.Entity<Gameweek>().HasMany(g => g.Fixtures);, all [Required] attributes and the [Key] attribute in Gameweek. Only the one-to-one mapping above and the [Key] attribute on Result.FixtureID is needed. Everything else will be mapped automatically based on conventions.