SaveChangesAsync期间EF Core中的DbUpdateConcurrenty异常

我使用Entity Framework Core时遇到以下错误:

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException
Attempted to update or delete an entity that does not exist in the store.
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryTable`1.Update(IUpdateEntry entry, IDiagnosticsLogger`1 updateLogger)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryStore.ExecuteTransaction(IList`1 entries, IDiagnosticsLogger`1 updateLogger)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryDatabase.SaveChangesAsync(IList`1 entries, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(StateManager stateManager, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Personnel.Infrastructure.Repositories.Persons.PersonWriteRepository.UpdateAsync(Person person, CancellationToken cancellationToken) in C:\Users\user\RiderProjects\staffpro.learn.redkozubov\src\Services\Personnel\Infrastructure\Personnel.Infrastructure.Repositories\Persons\PersonWriteRepository.cs:line 54
   at Personnel.Unit.RepositoryTests.Persons.Write.PersonWriteRepositoryPositiveTests.UpdateAsync_WithWorkExperience_AddsPersonAndContext(Person person, WorkExperienceDto workExperienceDto, PersonWriteRepository writeRepository, PersonReadRepository readRepository) in C:\Users\user\RiderProjects\staffpro.learn.redkozubov\src\Services\Personnel\Tests\Personnel.Unit\RepositoryTests\Persons\Write\PersonWriteRepositoryPositiveTests.cs:line 71
   at Xunit.Sdk.TestInvoker`1.<>c__DisplayClass48_0.<<InvokeTestMethodAsync>b__1>d.MoveNext() in /_/src/xunit.execution/Sdk/Frameworks/Runners/TestInvoker.cs:line 276
--- End of stack trace from previous location ---
   at Xunit.Sdk.ExecutionTimer.AggregateAsync(Func`1 asyncAction) in /_/src/xunit.execution/Sdk/Frameworks/ExecutionTimer.cs:line 48
   at Xunit.Sdk.ExceptionAggregator.RunAsync(Func`1 code) in /_/src/xunit.core/Sdk/ExceptionAggregator.cs:line 90

当我尝试使用以下命令将更改保存到实体时,会发生此错误

await _personnelContext.SaveChangesAsync(cancellationToken) 

尝试更新后 Person 关联实体 WorkExperience .

代码如下:

[Theory]
[MemberData(nameof(ValidTestDataGenerator.GetPersonWithWorkExperienceDataAndRepositories), MemberType = typeof(ValidTestDataGenerator))]
internal async Task UpdateAsync_WithWorkExperience_AddsPersonAndContext(Person person, WorkExperienceDto workExperienceDto, PersonWriteRepository writeRepository, PersonReadRepository readRepository)
{
    // Arrange
    await writeRepository.AddAsync(person);

    var dbPerson = await readRepository.GetByIdAsync(person.Id);

    dbPerson.AddWorkExperience(
        workExperienceDto.Id,
        workExperienceDto.JobTitle,
        workExperienceDto.Street,
        workExperienceDto.Country,
        workExperienceDto.City,
        workExperienceDto.Description,
        workExperienceDto.HiringDate,
        workExperienceDto.OrganizationName,
        workExperienceDto.DismissalDate
    );

    // Act
    await writeRepository.UpdateAsync(dbPerson);

    // Assert
    dbPerson.Should().BeEquivalentTo(person);
}

存储库:

public class PersonReadRepository
{
    private readonly DbSet<Person> _persons;

    public PersonReadRepository(PersonnelContext personnelContext)
    {
        _persons = personnelContext.Set<Person>();
    }

    public async Task<Person?> GetByIdAsync(Guid id, CancellationToken cancellationToken = default)
    {
        return await _persons.FindAsync(id, cancellationToken);
    }
}

public class PersonWriteRepository
{
    private readonly DbSet<Person> _persons;
    private readonly PersonnelContext _personnelContext;

    public PersonWriteRepository(PersonnelContext personnelContext, IPersonReadRepository personReadRepository)
    {
        _personnelContext = personnelContext;
        PersonReadRepository = personReadRepository;
        _persons = personnelContext.Set<Person>();
    }

    public IPersonReadRepository PersonReadRepository { get; }

    public async Task AddAsync(Person person, CancellationToken cancellationToken = default)
    {
        await _persons.AddAsync(person, cancellationToken);
        await _personnelContext.SaveChangesAsync(cancellationToken);
    }

    public async Task UpdateAsync(Person person, CancellationToken cancellationToken = default)
    {
        _persons.Update(person);
        await _personnelContext.SaveChangesAsync(cancellationToken);
    }
}

可能的原因是什么 DbUpdateConcurrencyException 在这种情况下出现错误,我该如何修复它?我应该实现乐观并发控制,还是我处理实体更新或状态跟踪的方式有问题?

错误 DbUpdate并发异常 当我打电话的时候

await _personnelContext.SaveChangesAsync(cancellationToken);

里面 UpdateAsync 方法 PersonWriteRepository .

我添加了一个 人 通过以下方式访问数据库 AddAsync 。然后我更新 人 通过添加一些 工作经历 个人导航属性中的数据 ICollection<WorkExperience> WorkExperiences .

更新失败,出现上述错误。

在更新之前,我检查了实体是否处于正确的状态,但仍然得到错误。