实体框架：使用 Code First 方法定义关系

Question

作为 Entity Framework 及其方法的新手，我有几个模型 classes，我想使用它们通过代码优先方法创建数据库表。 Usermodel 的 id 引用了 2 个表，并为每个表指向至少 2 列，如下所示。

    public class ControlGroup
    {

        public int ControlGroupId { get; set; }

        public string ControlGroupName { get; set; }

        public virtual User CreatedBy { get; set; }

        public DateTime CreationTime { get; set; }

        public virtual User UpdatedBy { get; set; }

        public DateTime UpdateTime { get; set; }

    }

    public class ControlPoint
    {

        public int ControlPointId { get; set; }

        public string ControlPointName { get; set; }

        public virtual User CreatedBy { get; set; }

        public DateTime CreationTime { get; set; }

        public virtual User UpdatedBy { get; set; }

        public virtual User Auditor{ get; set; }

        public DateTime UpdateTime { get; set; }

    }

    public class User
    {

        public string UserId { get; set; }

        public string UserFirstName { get; set; }

        public string UserLastName { get; set; }

        public string UserPassword { get; set; }

        public string UserEmail { get; set; }

        public virtual UserType UserType { get; set; }

    }

我已经在 ControlGroup 和 ControlPoint class 中定义了 User 但我对如何在 User 中定义关系感到困惑 class。我是否需要为其他两个 class 中的每个 User 对象在 User 中添加 5 个属性，还是只需要一个就足够了？任何帮助将不胜感激。

Answer 1

添加到您的所有 classes ID 字段
为用户添加导航属性class
我假设您在 User 和 ControlPoint、ControlGroup 实体之间有 one-to-many 关系。
我从User中删除了字段UserType，因为你没有显示UserType class 声明并且没有指定它们之间的关系（我不知道该怎么办，自己解决）。

最终模型将如下所示：

public class ControlGroup
{
    //was added
    public int ID { get; set; }

    public int ControlGroupId { get; set; }    
    public string ControlGroupName { get; set; }    
    public virtual User CreatedBy { get; set; }    
    public DateTime CreationTime { get; set; }    
    public virtual User UpdatedBy { get; set; }    
    public DateTime UpdateTime { get; set; }    
}

public class ControlPoint
{
    //was added
    public int ID { get; set; }

    public int ControlPointId { get; set; }    
    public string ControlPointName { get; set; }    
    public virtual User CreatedBy { get; set; }    
    public DateTime CreationTime { get; set; }    
    public virtual User UpdatedBy { get; set; }    
    public virtual User Auditor { get; set; }    
    public DateTime UpdateTime { get; set; }    
}

public class User
{
    //was added
    public int ID { get; set; }

    public string UserId { get; set; }    
    public string UserFirstName { get; set; }    
    public string UserLastName { get; set; }    
    public string UserPassword { get; set; }    
    public string UserEmail { get; set; }

    //on your own
    //public virtual UserType UserType { get; set; }

    //navigation properties one-to-many were added
    [InverseProperty("Auditor")]
    public virtual ICollection<ControlPoint> ControlPointAuditor { get; set; }
    [InverseProperty("UpdatedBy")]
    public virtual ICollection<ControlPoint> ControlPointUpdatedBy { get; set; }
    [InverseProperty("CreatedBy")]
    public virtual ICollection<ControlPoint> ControlPointCreatedBy { get; set; }    
    [InverseProperty("UpdatedBy")]
    public virtual ICollection<ControlGroup> ControlGroupUpdatedBy { get; set; }
    [InverseProperty("CreatedBy")]
    public virtual ICollection<ControlGroup> ControlGroupCreatedBy { get; set; }
    //navigation one-to-many
}

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