实体框架4.1代码第一外键ID

Question

我有两个实体引用了一对多.当实体框架创建表时,它会创建两个外键,一个用于我用Fluent接口指定的键,另一个用于ICollection.如何摆脱重复的外键？

public class Person
{
    public long RecordId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string Username { get; set; }

    public long DepartmentId { get; set; }
    public virtual Department Department { get; set; }
}

public class Department
{
    public long RecordId { get; set; }
    public string Name { get; set; }

    public virtual ICollection<Person> People { get; set; }
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Person>()
        .HasRequired(p => p.Department)
        .WithMany()
        .HasForeignKey(p => p.DepartmentId)
        .WillCascadeOnDelete(false);
}

谢谢!

Answer 1

您必须明确指定关联的多端:

modelBuilder.Entity<Person>()
    .HasRequired(p => p.Department)
    .WithMany(d => d.People)
    .HasForeignKey(p => p.DepartmentId)
    .WillCascadeOnDelete(false);

否则,EF将假定存在两个关联:一个未Department与Fluent代码中定义的类中的外键DepartmentId和导航属性一起公开- 另一个属于公开的导航属性但另一个未公开的关联结束并由EF自动创建外键.这是您在数据库中看到的另一个键.DepartmentPersonPeoplePerson

Answer 2

默认的Code First约定检测您的DepartmentId外键,因为它是传统的.我认为你应该删除Fluent定义:

modelBuilder.Entity<Person>()
    .HasRequired(p => p.Department)
    .WithMany()
    .WillCascadeOnDelete(false);