如何使用循环语句从CVS文件插入数据库

Question

我的代码有问题。我使用上传的逗号分隔（CSV）文件（其中有5行）插入数据库。第一行成功插入数据库，但是在第二个循环中插入第二行时遇到错误：

当IDENTITY_INSERT设置为OFF时，无法为表'bdoToDbs'中的标识列插入显式值。

这是我的循环码

            while (i < users.Count)
            {
                ViewBag.CompanyCode = users[i].CompanyCode;
                ViewBag.ProductCode = users[i].ProductCode;
                ViewBag.TransactionDate = users[i].TransactionDate;
                ViewBag.TransactionTime = users[i].TransactionTime;
                ViewBag.OriginatingBranch = users[i].OriginatingBranch;
                ViewBag.CustomerNumber = users[i].CustomerNumber;
                ViewBag.TransactionOrigin = users[i].TransactionOrigin;
                ViewBag.TypeOfPayment = users[i].TypeOfPayment;
                ViewBag.CheckNumber = users[i].CheckNumber;
                ViewBag.TransactionAmount = users[i].TransactionAmount;
                ViewBag.CustomerName = users[i].CustomerName;

                bdoToDb.CompanyCode = ViewBag.CompanyCode;
                bdoToDb.ProductCode = ViewBag.ProductCode;
                bdoToDb.TransactionDate = ViewBag.TransactionDate;
                bdoToDb.TransactionTime = ViewBag.TransactionTime;
                bdoToDb.OriginatingBranch = ViewBag.OriginatingBranch;
                bdoToDb.CustomerNumber = ViewBag.CustomerNumber;
                bdoToDb.TransactionOrigin = ViewBag.TransactionOrigin;
                bdoToDb.TypeOfPayment = ViewBag.TypeOfPayment;
                bdoToDb.CheckNumber = ViewBag.CheckNumber;
                bdoToDb.TransactionAmount = ViewBag.TransactionAmount;
                bdoToDb.CustomerName = ViewBag.CustomerName;
                bdoToDb.UserName = ViewBag.DisplayName;
                bdoToDb.UserIP = HttpContext.Connection.RemoteIpAddress.ToString();
                bdoToDb.UserDate = DateTime.Now.ToString("MM/dd/yyyy");
                i++;
                _context.Add(bdoToDb);
                await _context.SaveChangesAsync();
            });
            return RedirectToAction(nameof(Index));
        }

我的代码有问题。我使用上传的逗号分隔（CSV）文件（其中有5行）插入数据库。第一行已成功插入数据库，但在第二个循环中是...

Answer 1

关于EF核心的一个美丽之处在于，它跟踪更改，然后您可以一次保存就提交所有这些更改。如果您移动