c# - Entity Framework Core 设置拥有的实体在添加时为空

Question

我有下图:

public class Report
{
    public Guid Id { get; set; }
    public ICollection<EmployeeEntry> EmployeeEntries { get; set; }
}

public class EmployeeEntry
{
    public Guid Id { get; set; }
    public DateTimeOffset EntryDate { get; set; }
    public Address Address { get; set; }
}

public class Address
{
    public string City { get; set; }
    public string State { get; set; }
}

并且使用 fluentApi，我已将地址配置为 EmployeeEntry 实体拥有的实体，如下所示:

private void ConfigureEmployeeEntry(EntityTypeBuilder<EmployeeEntry> builder)
{
    builder.OwnsOne(x => x.Address, w =>
    {
        w.Property(x => x.City).HasMaxLength(100);
        w.Property(x => x.State).HasMaxLength(100);
    });
}

但是当我有多个 EmployeeEntry 的相同地址并运行以下代码时:

dbContext.Reports.Add(report);
dbContext.SaveChanges();

我得到以下异常:

The entity of type 'EmployeeEntry' is sharing the table 'report.EmployeeEntries' with entities of type 'EmployeeEntry.Address#Address', but there is no entity of this type with the same key value that has been marked as 'Added'. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the key values.

正如我注意到的，在 SaveChanges() 之前添加报告后，EF 将 Address 设置为 null。

我使用的是最新版本的 EntityFramework 核心。

Answer 1

But when I have the same Address for more than one EmployeeEntry

如果您指的是相同的地址 实例，Owned Entity Types 的 EF Core 文档明确声明目前不支持它 - 在 Limitations - Current shortcomings 下:

• Instances of owned entity types cannot be shared by multiple owners (this is a well-known scenario for value objects that cannot be implemented using owned entity types)

因此，要么确保您使用不同的实例(即使具有相同的属性值)，要么不使用拥有的实体类型，而是使用常规的实体类型和关系。