如何在代码优先中定义0..1到多个关系

Question

我正在阅读ado.net团队博客的文章，当时我发现如何创建一对一的关系，一对多的关系以及多对多的关系。但是，有没有办法创建0..1到多个关系？

class TestA
{
    public int id { get; set; }
    public string name { get; set; }
    [Timestamp]
    public byte[] stamp { get; set; }       
    public TestB TB { get; set; }
}

class TestB
{
    public int id { get; set; }
    public string name { get; set; }
    [Timestamp]
    public byte[] stamp { get; set; }
    public ICollection<TestA> TA { get; set; }
}

class myContext : DbContext
{
    public DbSet<TestA> players { get; set; }
    public DbSet<TestB> teams { get; set; }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<TestB>().HasOptional<TestA>(a => a);
    }
}

Thx inadvance！

Answer 1

你快到了。尝试将其映射如下。

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<TestA>().HasOptional(a => a.TB)
       .WithMany(b => b.TA);
}

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