Question

我目前有以下方法：

        public List<Order> GetOrders(int profileId, string timeSpan, string workOrd, string partNo, bool includeDeleted)
    {
        DateTime startDate = DateTime.Now;
        DateTime endDate = DateTime.Now;
        string[] times = (!string.IsNullOrWhiteSpace(timeSpan)) ? timeSpan.Trim().Split('-') : new string[] { "", "" };
        if (!string.IsNullOrWhiteSpace(times[0]) && !string.IsNullOrWhiteSpace(times[0]))
        {
            startDate = DateTime.Parse(times[0]).Date;
            endDate = DateTime.Parse(times[1]).Date;
        }

        //New Real Query
        IQueryable<Order_Travel> otQuery = _context.Order_Travels.Where(x =>
            (profileId != 0 || x.Profile.ProfileID == profileId)
            && ((timeSpan == null || timeSpan.Trim() == "") || ((DbFunctions.TruncateTime(x.TimeRecieved) >= startDate) 
                                                            && (DbFunctions.TruncateTime(x.TimeRecieved) <= endDate)))
            && ((workOrd == null || workOrd.Trim() == "") || x.Order.WorkOrdNo == workOrd)
            && ((partNo == null ||partNo.Trim() == "") || x.Order.PartNo == partNo)
            && (!includeDeleted || x.Aborted == true));

        //The results is now in order_travel. Under here binding them to a list of orders with only the respective orderTravels included.
        List<Order> orders = new List<Order>();
        List<Order_Travel> ots = otQuery.ToList();
        foreach (Order_Travel ot in ots)
        {
            var OrderInList = orders.FirstOrDefault(X => X == ot.Order);
            if (OrderInList == null)
            {
                orders.Add(ot.Order);
                OrderInList = orders.FirstOrDefault(X => X == ot.Order);
                OrderInList.OrderTravels.Clear();
                OrderInList.OrderTravels.Add(ot);
            }
            else
            {
                OrderInList.OrderTravels.Add(ot);
            }
        }
        return orders;
    }

我需要做的是（正如我尝试的那样）进行调用，查找与发送给它的参数匹配的所有Order_Travel对象。如果某些（或全部）留空，则无论值如何，都会占用所有内容。现在的代码，如果进行空白搜索（没有任何参数的搜索），则不会返回任何内容，我看不出可能是什么问题。我试过调试它，但没有运气。

非常感谢任何帮助！

谢谢！

Answer 1

一次过滤一个选项，而不是尝试将所有内容放入单个表达式中：

IQueryable<T> query = all;    // start with everything

if (IsPresent(option1))
{
   query = query.Where(t => t.XXX == option1);   
}

实施例

IQueryable<Order_Travel> otQuery = _context.Order_Travels;

if (profileId != 0)
{
    otQuery = otQuery.Where(x => x.Profile.ProfileID == profileId);
}

if (timeSpan != null && timeSpan.Trim() != "")
{
    otQuery = otQuery.Where(x => DbFunctions.TruncateTime(x.TimeRecieved) >= startDate &&
                                 DbFunctions.TruncateTime(x.TimeRecieved) <= endDate);
}

你也会发现这比一个巨大的表达更容易维护。

Answer 2

可能这部分是你的问题：

(profileId != 0 || x.Profile.ProfileID == profileId)

应该是

(profileId == 0 || x.Profile.ProfileID == profileId)

如果您的个人资料ID为0，则只会找到x.Profile.ProfileID为0的条目。可能没有这样的条目。

IQueryable只有可选参数

2 个答案: