Entity Framework 7 Code First中的一对一关系
问题描述：
如何首先使用数据注释或Fluent Api在Entity Framework 7代码中配置一对一或零或一对一关系？
How to configure One-to-One or ZeroOrOne-to-One relationships in Entity Framework 7 Code First using Data Annotations or Fluent Api?
答
您可以在Entity Framework 7中使用Fluent API定义OneToOne关系，如下所示：
You can define OneToOne relationship using Fluent API in Entity Framework 7 as below
class MyContext : DbContext
{
public DbSet<Blog> Blogs { get; set; }
public DbSet<BlogImage> BlogImages { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.HasOne(p => p.BlogImage)
.WithOne(i => i.Blog)
.HasForeignKey<BlogImage>(b => b.BlogForeignKey);
}
}
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
public BlogImage BlogImage { get; set; }
}
public class BlogImage
{
public int BlogImageId { get; set; }
public byte[] Image { get; set; }
public string Caption { get; set; }
public int BlogForeignKey { get; set; }
public Blog Blog { get; set; }
}