Entity Framework 中的映射异常

Question

我有一个用于多语言应用程序的大数据库，它从服务器获取文本，插入数据库，然后根据用户首选语言找到合适的文本。

先描述一下数据库再说下我的问题：插图：例如，我有一个 table Product，它有一个指向 Translation table 的外键（Description 列），后者又连接到 TranslationEntry table 包含所有语言的产品描述的所有翻译。

这些语言位于一个名为 Language 的单独 table 中，它有一个指向 TranslationEntry table.

的外键

public class Product : BaseModel
{
    public int description { get; set; }
    public virtual Translation Description { get; set; }
}

public class Translation : BaseModel
{
    public Translation()
    {
        Products = new List<Product>();
    }
    public virtual ICollection<Product> Products { get; set; }
    public virtual ICollection<MainCategory> MainCategories { get; set; }
    public virtual ICollection<Caption> Captions { get; set; }
}

public class TranslationEntry : BaseModel
{
    public string text { get; set; }
    public int language { get; set; }
    public virtual Language Language { get; set; }
    public int translation { get; set; }
    public virtual Translation Translation { get; set; }
}

public class Language : BaseModel
{
    public Language()
    {
        TranslationEntries = new List<TranslationEntry>();
    }

    public string title { get; set; }
    public string language_code { get; set; }
    public virtual ICollection<TranslationEntry> TranslationEntries { get; set; }
}

public  class BaseModel
{
    public  int id { get; set; }
    public  int MembershipId { get; set; }
    public  SyncStatus SyncState { get; set; }
    ....
}

翻译条目映射：

        HasRequired(translationEntry => translationEntry.Translation)
            .WithMany(translation => translation.TranslationEntries)
            .HasForeignKey(translationEntry =>
                new {translationEntry.translation, translationEntry.MembershipId, translationEntry.SyncState})
                .WillCascadeOnDelete(false);

        HasRequired(translationEntry => translationEntry.Language)
            .WithMany(language => language.TranslationEntries)
            .HasForeignKey(translationEntry =>
                new {translationEntry.language, translationEntry.MembershipId, translationEntry.SyncState})
                .WillCascadeOnDelete(false);

        Property(t => t.translation)
            .HasColumnAnnotation("Index", new IndexAnnotation(new IndexAttribute("IX_translatinlanguageOd", 1) { IsUnique = true }));
        Property(t => t.language)
            .HasColumnAnnotation("Index", new IndexAnnotation(new IndexAttribute("IX_translatinlanguageOd", 2) { IsUnique = true }));

产品映射：

HasRequired(product => product.Description)
            .WithMany(translation => translation.Products)
            .HasForeignKey(product => new { product.description, product.MembershipId, product.SyncState })
            .WillCascadeOnDelete(false);

此处为样本数据集：

现在的问题是：我想获取产品的描述，我使用以下命令

var o = databaseContext.Products.ToList().First(p=>p.id==1)?.Description.TranslationEntries.First(te=>te.language==1);

但是我得到一个错误：

A 'Mapping' exception occurred while processing the query. See the inner exception.

Inner exception:
More than one property map found for property 'translation' when using case-insensitive search.

请注意，有许多实体与我展示的 Product table 具有相同的翻译关系。

UPDATE: 我的临时解决方案是：

var Language = context.Languages.Include(l => l.TranslationEntries)
                        .Where(l => l.id == languageId)
                        .ToList()
                        .FirstOrDefault();
TranslationEntries = Language?.TranslationEntries;
var translatedText = (from t in TranslationEntries where t.translation == 2 select t.text).FirstOrDefault();

Answer 1

终于解决了这个愚蠢的问题！正如错误消息所说，问题是通过不区分大小写的搜索在 TranslationEntry Class 中有 2 个属性命名翻译，我重命名了其中一个，现在一切正常！

Entity Framework 中的映射异常

Mapping exception in Entity Framework

c#

sql-server

entity-framework

ef-fluent-api