如何处理控制器中的一对多关系 [英] How to handle one to many relationship in controller

问题描述

你好程序员，请跟我一起讨论我的问题，因为我正在学习ASP.NET MVC。





我有两个类：鞋子和颜色。



鞋子有很多颜色。



鞋子实体

Hello Programmers, Please bear with me with the way i am going to ask my question because i am learning ASP.NET MVC on my own.


I have two class : Shoe and color.

A shoe will have many colors.

Shoe Entity

public string shoeId{get;set;}
public string BrandName {get;set;}
public string Size {get;set:}
public virtual string ColorId {get;set:}
[ForeignKey("ColorId")]
public virtual ICollection(Color) Colors {get;set;}

颜色实体

Color Entity

public string ColorId {get;set;}
public string ColorName {get;set;}
public string PictureSamnple {get;set;}
public virtual string shoeId {get;set:}

如果我在控制器中构建两个实体，我将遇到问题尝试创建新鞋时使用create方法。

如果我使用@ Html.HiddenFor（e => e.ColorId）

@ Html.HiddenFor（e => e.shoeId）在SHoe的Create视图中，我在尝试提交时会出错。



我想要的是，当你重新创建鞋子时，你也会在提交之前创建一种颜色，但这有点困难。请帮助我。

If i scaffold both entitys in the controller, i will have problem with the create method when trying to Create a new Shoe.
If i use @Html.HiddenFor(e => e.ColorId)
@Html.HiddenFor(e => e.shoeId) in the Create view of SHoe, i will get an error when trying to submit.

what i am trying to achive is that when you re creating the shoe, you will also create a color before submitting it but it is kind of difficult. please, help me.

推荐答案

使用流畅的api以有效的方式映射实体。例如，您可以按照以下方式映射鞋子和颜色之间的一对多关系 -

Use fluent api for mapping entities in efficient way. For example you can map the one to many relationship between shoe and colors in following way -

public class ShoeMapper : EntityTypeConfiguration<Shoe>
    {
        public ShoeMapper()
        {
            HasMany(x => x.Colors).WithRequired().HasForeignKey(x => x.ShoeId);
        }
    }

除此之外你应该创建一个单独的表

Apart from this you should create a separate table

tbl_Colors

[int_Id, varchar_Name]

然后是联结表

tbl_Shoes_Colors

[fk_Shoes_Id, fk_Colors_Id, varchar_SampleImage]

按照规范化建议映射关系。

to map relation as per normalization recommendation.

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