无法映射属性“PropertyName"，因为它属于“List<decimal>"类型 [英] The property &#39;PropertyName&#39; could not be mapped, because it is of type &#39;List&lt;decimal&gt;&#39;

问题描述

当我尝试使用 EntityFramework Core 创建数据库时遇到了这个问题:

I got this problem when I try to create the database with EntityFramework Core:

无法映射属性Rating.RatingScores"，因为它属于List"类型，它不是受支持的原始类型或有效的实体类型.显式映射此属性，或使用[NotMapped]"属性或使用OnModelCreating"中的EntityTypeBuilder.Ignore"忽略它.

The property 'Rating.RatingScores' could not be mapped, because it is of type 'List' which is not a supported primitive type or a valid entity type. Either explicitly map this property, or ignore it using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

这是课程:

public class Rating
{
    public int Id { get; set; }

    public List<decimal> RatingScores { get; set; }

    public decimal Score
    {
        set => Score = value;
        get => Math.Round(RatingScores.Sum() / RatingScores.Count, 1);
    }
}

推荐答案

如果 Rating 类有多个 RatingScores 则是一对多关系，并且 RatingScores 属性需要自己的表，因此需要创建一个新类.

If the Rating class has multiple RatingScores you have a one-to-many relationship and the RatingScores property needs its own table, you therefore need to create a new class.

Class RatingScore 
{
  public int Id { get; set; }
  public decimal RtSc { get; set; }
}

那么 Rating 属性将如下所示:

Then the Rating property will look like this:

public List<RatingScore> MyRatingScores { get; set; }

但是，如果每个评级都有一个 RatingScore，则您的资产不应该是一个集合.

However if each Rating has one RatingScore, your property should not be a collection.

public RatingScore MyRatingScore { get; Set; }

这篇关于无法映射属性“PropertyName"，因为它属于“List<decimal>"类型的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！