在 asp.net core 中插入/更新记录时出错

Question

当我尝试插入/更新记录时，出现以下错误。

无法跟踪实体类型的实例，因为已跟踪另一个具有相同 {'Id'} 键值的实例。

下面是我的代码。在这里，我通过以 1 递增的方式创建/生成 ID（主键）。我在保存和更新时都遇到错误

public bool SaveDataCapDetails(List<TDataCapDetails> lstDataCapDetails)
        {
            bool IsSuccess = false;

            using (var dbContextTransaction = _objContext.Database.BeginTransaction())
            {
                try
                {

                    List<TDataCapDetails> lstDataCapDetailsRecords = null;

                    if (lstDataCapDetails.Where(x => x.Id == 0).Count() > 0)
                    {
                        lstDataCapDetailsRecords = new List<TDataCapDetails>();
                        lstDataCapDetailsRecords.InsertRange(0, lstDataCapDetails);

                        int? id = _objContext.TDataCapDetails.Max(x => (int?)x.Id);
                        id = id == null ? 0 : id;
                        foreach (var item in lstDataCapDetailsRecords.Where(x => x.Id == 0))
                        {
                            id = id + 1;
                            item.Id = (int)id;
                        }
                        _objContext.Entry(lstDataCapDetailsRecords).State = EntityState.Detached;
                        _objContext.AddRange(lstDataCapDetailsRecords);
                        _objContext.SaveChanges();
                    }

                    if (lstDataCapDetails.Where(x => x.Id > 0).Count() > 0)
                    {
                        lstDataCapDetailsRecords = new List<TDataCapDetails>();
                        lstDataCapDetailsRecords = lstDataCapDetails.Where(x => x.Id > 0).ToList();
                        _objContext.UpdateRange(lstDataCapDetailsRecords);
                        _objContext.SaveChanges();
                    }

                    dbContextTransaction.Commit();
                }
                catch (Exception ex)
                {
                    dbContextTransaction.Rollback();
                    throw ex;
                }
            }

            return IsSuccess;
        }

我从业务层调用的上述方法如下

bool success = dal.SaveDataCapDetails(lstDataCapDetails)

我已尝试使用 AsNoTracking 和其他可用选项，但仍然无法解决此问题。

对此的任何帮助表示赞赏。

Answer 1

如果你想有表Primary-Key，并与Identity-Incremental您必须创建您的Table设置后ForeignKey，你必须设置Identity-Incremental为ForeignKey。喜欢：

对于此问题，您的代码更改为：

    public bool SaveDataCapDetails(List<TDataCapDetails> lstDataCapDetails)
    {
        bool IsSuccess = false;

        using (var dbContextTransaction = _objContext.Database.BeginTransaction())
        {
            try
            {

                List<TDataCapDetails> lstDataCapDetailsRecords = null;

                if (lstDataCapDetails.Where(x => x.Id == 0).Count() > 0)
                {
                    lstDataCapDetailsRecords = new List<TDataCapDetails>();
                    _objContext.AddRange(lstDataCapDetailsRecords);
                    _objContext.SaveChanges();
                }

                if (lstDataCapDetails.Where(x => x.Id > 0).Count() > 0)
                {
                    lstDataCapDetailsRecords = new List<TDataCapDetails>();
                    lstDataCapDetailsRecords = lstDataCapDetails.Where(x => x.Id > 0).ToList();
                    _objContext.UpdateRange(lstDataCapDetailsRecords);
                    _objContext.SaveChanges();
                }

                dbContextTransaction.Commit();
            }
            catch (Exception ex)
            {
                dbContextTransaction.Rollback();
                throw ex;
            }
        }

        return IsSuccess;
    }