c# - 在进行交易时无法找到实体

Question

我遇到了这个数据层方法的问题

    public async Task<(bool HasFailed, IList<string> ErrorMessages)> ApproveBillCancelRequest(IEnumerable<string[]> billsToApprove,
        string userId, string operationId)
    {
        var callerInfo = Shared.CommonAcross.Helper.GetCaller();
        InfoScope($"{LayerName} -> {callerInfo.MethodName} -> Started", operationId, userId);

        var errorMessages = new List<string>();

        using (var context = new FocusConnection())
        {
            var transaction = context.Database.BeginTransaction();

            try
            {
                foreach (var billToApprove in billsToApprove)
                {
                    var targetBillNumber = billToApprove[0];
                    var targetPayModeId = int.Parse(billToApprove[1]);

                    var entityBill = context.BILL_INFO_CANCEL_REQUESTS
                        .SingleOrDefault(where =>
                            where.BILL_NUMBER == targetBillNumber &&
                            where.PAY_MODE_ID == targetPayModeId);

                    if (entityBill == null)
                    {
                        errorMessages.Add($"Bill #{billToApprove[0]}, payment #{billToApprove[1]} was not found for cancel approval");
                        continue;
                    }

                    entityBill.BILL_INFO.LAST_MODIFIED_BY = userId;
                    entityBill.BILL_INFO.STAMP_DATE = DateTime.Now;
                    entityBill.BILL_INFO.INPUT_STATUS = 0;

                    var cancelledBill = new BILL_INFO_CANCELED
                    {
                        BILL_NUMBER = entityBill.BILL_NUMBER,
                        PAY_MODE_ID = entityBill.PAY_MODE_ID,
                        CASHIER_ID = entityBill.CASHIER_ID,
                        CANCELED_DATE = entityBill.CANCEL_REQUEST_DATE,
                        CANCEL_REQUESTED_BY = entityBill.CANCEL_REQUESTED_BY,
                        CANCEL_APPROVED_BY = userId,
                        REMARKS = entityBill.CANCELATION_REASON
                    };

                    // Add cancelled bill
                    context.BILL_INFO_CANCELEDS.Add(cancelledBill);

                    // Remove cancellation request
                    context.BILL_INFO_CANCEL_REQUESTS.Remove(context.BILL_INFO_CANCEL_REQUESTS.Single(where =>
                        where.BILL_NUMBER == cancelledBill.BILL_NUMBER && where.PAY_MODE_ID == cancelledBill.PAY_MODE_ID));

                    await context.SaveChangesAsync();
                }

                transaction.Commit();
            }
            catch (Exception exp)
            {
                transaction?.Rollback();

                ErrorScope($"{LayerName} -> {callerInfo.MethodName} -> Exception [{exp.Message}]", exp, operationId, userId);
                errorMessages.Add($"{LayerName} -> {callerInfo.MethodName} -> Exception [{exp.Message}]");

                return (true, errorMessages);
            }
        }

        return (errorMessages.Any(), errorMessages);
    }

问题是在 ForEach 循环中，第一条记录被正确检索和处理。但是剩余的记录永远找不到（entityBill == null），但它们在数据库中。我相信这与正在运行的事务有关。

任何人都可以帮忙吗？

标签： c#entity-framework-6

Answer 1

这是一个很难破解的。事实证明，当 UI 层上的 String.Splitting() 时，有一个额外的空间被附加到数组列表中数组的第一个索引。所以我通过以下方式解决了这个问题：

var targetBillNumber = billToApprove[0].Trim();
var targetPayModeId = int.Parse(billToApprove[1].Trim());