使用数据注释创建外键 [英] Create Foreign Key using Data Annotations

问题描述

在下面的代码中，我需要在ParentInfoAddProperties.ParentQuestionAnswersId上设置一个外键constrant，以便它依赖于ParentQuestionAnswers.Id（这是一个主键）。我试图使用数据注释，但实体框架6想在我的ParentQuestionAnswers表中创建一个新的外键列，它引用了ParentInfoAddProperties.Id列而不是ParentInfoAddProperties.ParentQuestionAnswersId列。我不希望实体框架创建一个新的外键列。

In the code below, I need to set a foreign key constrant on ParentInfoAddProperties.ParentQuestionAnswersId so that it is dependent on ParentQuestionAnswers.Id (which is a Primary Key). I am attempting to do so using data annotations but Entity Framework 6 wants to create a new Foreign Key column in my ParentQuestionAnswers table which references the ParentInfoAddProperties.Id column not the ParentInfoAddProperties.ParentQuestionAnswersId column. I do not want Entity Framework to create a new foreign key column.

如果有人可以解释什么数据注释或（如有必要）流畅的映射，我应该非常感谢指定实现期望的外键驻留。感谢提前。

I'd greatly appreciate if someone can explain what data annotations or (if necessary) fluent mappings I should specify to achieve the desired foreign key constrant. Thanks in advance.

namespace Project.Domain.Entities
{  
    public class ParentQuestionAnswers
    {
        public ParentQuestionAnswers()
        {
            ParentInfoAddProperties = new ParentInfoAddProperties();
        }

        [Required]
        public int Id { get; set; }

        [Required]
        public int UserId { get; set; }

        public ParentInfoAddProperties ParentInfoAddProperties { get; set; }
    }

    public class ParentInfoAddProperties
    {
        [Required]
        public int Id { get; set; }

        [Required]
        public int ParentQuestionAnswersId { get; set; }
    }
}

推荐答案

您可以使用以下数据注释，并使用实体代替int

You could use the following data annotation, and use entity instead of int

[Required]
[ForeignKey("ParentQuestionAnswers")]
public ParentQuestionAnswers ParentQuestionAnswers { get; set; }

获取ID只能添加属性

public int ParentQuestionAnswersId { get; set; }

但您仍然需要 ParentQuestionAnswers 属性所以EF会明白你的意思

but you still need the ParentQuestionAnswers property so EF will understand you .

（这些代码行应位于 ParentInfoAddProperties 类）

(these code rows should be under the ParentInfoAddProperties class)

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