LINQ 连接 2 个具有 DateTimeOffset 外键的表

Question

当两个表共享数据类型为 DateTiimeOffset 的外来组合键时，如何连接它们？

请参考以下查询。

from o in outstandingOrders
join d in dispatchAdvicedOrders
on new { o.ExpectedDeliveryDate, o.JobNumber } equals new { d.ExpectedDeliveryDate, d.JobNumber } into oD
from d in oD.DefaultIfEmpty()
select new DeliverySchedule
{
    ExpectedDeliveryDate = o.ExpectedDeliveryDate,
    JobNumber = o.JobNumber,
    OutstandingWeight = o.Weight,
    DispatchAdvicedWeight = d.Weight
};

专注于线路

on new { o.ExpectedDeliveryDate, o.JobNumber } equals new { d.ExpectedDeliveryDate, d.JobNumber } into oD

所有
1. ExpectedDeliveryDate 的数据类型为 DateTimeOffset 所有
JobNumber
2. 的日期类型为string

我的问题

我应该使用
1. DateTimeOffset.Compare()

    进行上述查询吗？

如果可以，我该如何使用它？

Answer 1

是你想要的吗？

from o in outstandingOrders
join d in dispatchAdvicedOrders
on new { o.ExpectedDeliveryDate, o.JobNumber } equals new { d.ExpectedDeliveryDate, d.JobNumber } into oD
from d in oD.DefaultIfEmpty()
select new DeliverySchedule
{
    ExpectedDeliveryDate = o.ExpectedDeliveryDate,
    JobNumber = o.JobNumber,
    OutstandingWeight = o.Weight,
    DispatchAdvicedWeight = d != null ? d.Weight : null // Handle null values in case of outer join
};