我正在为一个C#>Sql Server应用程序编写单元测试。MS建议在不使用生产数据库进行测试时使用SQLite（https：//learn.microsoft.com/en-us/ef/core/testing/testing-without-the-database#inmemory-provider）。我有SQLite设置，我试图用测试数据填充数据库。我将一个生产数据样本导出为JSON格式，并将其与测试项目一起保存，这样我就可以相当容易地更新测试数据。设置SQLite上下文的代码我取自MS文章
除了这个块，没有行号可以引用

var memoryData = new ReqestDataInMemory();
  var data = memoryData.AllRepositoryRequests();

获取json并将复杂对象结构作为IEnumberable返回。然后我尝试将其保存到db上下文。

public class TestDbContext
    {
        public SqliteConnection _connection {get; set;} 
        public DbContextOptions<TaxonomyContext> _contextOptions { get; set;}

        public TestDbContext()
        {
            // Create and open a connection. This creates the SQLite in-memory database, which will persist until the connection is closed
            // at the end of the test (see Dispose below).
            _connection = new SqliteConnection("Filename=:memory:");
            _connection.Open();

            // These options will be used by the context instances in this test suite, including the connection opened above.
            _contextOptions = new DbContextOptionsBuilder<TaxonomyContext>()
                .UseSqlite(_connection)
                .Options;

            // Create the schema and seed some data
            using var context = new TaxonomyContext(_contextOptions);

            if (context.Database.EnsureCreated())
            {
                using var viewCommand = context.Database.GetDbConnection().CreateCommand();
                viewCommand.CommandText = @"
                    CREATE VIEW AllRequests AS
                    SELECT Url
                    FROM Request";
                viewCommand.ExecuteNonQuery();
            }

            var memoryData = new ReqestDataInMemory();
            var data = memoryData.AllRepositoryRequests();

            context.AddRange(data);
            context.SaveChanges();
        }

AddRange()抛出错误

System.InvalidOperationException : The instance of entity type 'RequestType' cannot be tracked because another instance with the same key value for {'RequestTypeId'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached.

这是有意义的，如果它试图保存查找表一遍又一遍。这就是我的问题。
这是我正在处理的对象。RequestType是我遇到阻塞器的地方，它是一个简单的查找表RequestType.Id and RequestType.Name。Status是一对多查找表。所有的FK关系都回到Request
ChangeDetail对象是请求的详细信息。它具有唯一的ID和请求的FK。
我试着将RequestType和Statuses都设为空，但它

public class Request
    {
        public int RequestId { get; set; }
        /// <summary>changed from "navarchar(max)" to "text" for sqlite testing db </summary>
        [Required]
        [MinLength(50)]
        [Column(TypeName = "text")]
        public string Justification { get; set; } = string.Empty;
        [Required]
        public int SubmitUser { get; set; }
        [Required]
        public DateTime SubmitDate { get; set; }
        public int? ModifyUser { get; set; }
        public DateTime? ModifyDate { get; set; }
        public virtual IEnumerable<ChangeDetail> ChangeDetail { get; set; } = new List<ChangeDetail>();
        public virtual IEnumerable<Status> Statuses { get; set; } = new List<Status>();
        public virtual RequestType RequestType { get; set; } = new RequestType();
    }

我的查询工作很好，所以我认为我所有的关系都很稳固。为了以防万一，这里有一些关系。

protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Request>()
                .HasOne(x => x.RequestType)
                .WithMany(x => x.Requests);

            modelBuilder.Entity<Request>()
                .HasMany(x => x.ChangeDetail)
                .WithOne(x => x.Request);

            modelBuilder.Entity<Request>()
                .HasMany(x => x.Statuses)
                .WithMany(x => x.Requests);

            modelBuilder.Entity<Status>()
                .HasOne(x => x.RequestStatusType)
                .WithMany(x => x.Statuses);
        }

为了解决这个问题，我尝试了这个：LINQ query to return distinct field values from list of objects
我认为这显示了承诺，使用实体。未修改，但不能让它工作Save detached entity in Entity Framework 6
这谈到的FK，我有设置，但也许它没有参考他们保存？How do I stop Entity Framework from trying to save/insert child objects?
我很感激你的任何建议。