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如果连接表是模式的一部分,如何在EF Core中指定多对多关系?

entity-framework-core .net c#

Daniel Jonsson · 技术社区 · 2 年前

在…上 https://docs.microsoft.com/en-us/ef/core/modeling/relationships?tabs=fluent-api%2Cfluent-api-simple-key%2Csimple-key#joining-relationships-configuration 下面是如何在Entity Framework Core中指定多对多关系的示例:

modelBuilder.Entity<Post>()
    .HasMany(p => p.Tags)
    .WithMany(p => p.Posts)
    .UsingEntity<Dictionary<string, object>>(
        "PostTag",
        j => j
            .HasOne<Tag>()
            .WithMany()
            .HasForeignKey("TagId")
            .HasConstraintName("FK_PostTag_Tags_TagId")
            .OnDelete(DeleteBehavior.Cascade),
        j => j
            .HasOne<Post>()
            .WithMany()
            .HasForeignKey("PostId")
            .HasConstraintName("FK_PostTag_Posts_PostId")
            .OnDelete(DeleteBehavior.ClientCascade));

我该如何做同样的事情,但要具体说明这一点 PostTag 架构的一部分不是默认的吗?

例如, Test.PostTag 和 [Test].[PostTag] 不要工作。尝试访问资源时,只会导致异常 Microsoft.Data.SqlClient.SqlException: 'Invalid object name 'PostTag'.' 被扔了。所以它似乎忽略了模式名 Test 当我试图指定它时。

0 回复 | 直到 2 年前

Daniel Jonsson 2 年前

我所做的就是按照他们在页面上写的做 https://www.learnentityframeworkcore.com/configuration/many-to-many-relationship-configuration .在他们的例子中,他们有以下两类:

public class Book
{
    public int BookId { get; set; }
    public string Title { get; set; }
    public Author Author { get; set; }
    public ICollection<BookCategory> BookCategories { get; set; }
}  
public class Category
{
    public int CategoryId { get; set; }
    public string CategoryName { get; set; }
    public ICollection<BookCategory> BookCategories { get; set; }
}

然后他们制作了以下课程,通过多对多关系将他们联系起来:

public class BookCategory
{
    public int BookId { get; set; }
    public Book Book { get; set; }
    public int CategoryId { get; set; }
    public Category Category { get; set; }
}

然后它们有以下配置:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<BookCategory>()
        .HasKey(bc => new { bc.BookId, bc.CategoryId });  
    modelBuilder.Entity<BookCategory>()
        .HasOne(bc => bc.Book)
        .WithMany(b => b.BookCategories)
        .HasForeignKey(bc => bc.BookId);  
    modelBuilder.Entity<BookCategory>()
        .HasOne(bc => bc.Category)
        .WithMany(c => c.BookCategories)
        .HasForeignKey(bc => bc.CategoryId);
}

在我的例子中,我将连接类配置为:

internal class AccountRuleEntityTypeConfiguration : IEntityTypeConfiguration<CompAccountRule>
{
    public void Configure(EntityTypeBuilder<AccountRule> builder)
    {
        builder
            .ToTable("AccountRules", "Compliance");
        builder
            .HasKey(x => new { x.AccountId, x.RuleInstanceId });
        builder
            .HasOne(x => x.Account)
            .WithMany(x => x.AccountRules)
            .HasForeignKey(x => x.AccountId);
        builder
            .HasOne(x => x.RuleInstance)
            .WithMany(x => x.AccountRules)
            .HasForeignKey(x => x.RuleInstanceId);
    }
}

Account 属于默认名称空间, RuleInstance 属于 Compliance 名称空间,以及这个连接表 AccountRule 也属于 顺从 名称空间,我可以通过语句来配置它 builder.ToTable("AccountRules", "Compliance"); .