使用Linq检查日期在范围内

本文介绍了使用Linq检查日期在范围内的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我目前正在做一些事情，需要我检查两个日期之间的可用性.我当前的方法没有返回预期的结果.例如，说我有以下保留:

I'm currently working on something which requires me to check availability between two dates. My current methods aren't returning the expected result. For example, say I have the following reservations:

• 2015年13月13日至2015年4月18日
• 2015年15月15日至2015年4月20日
• 2015年10月4日至2015年4月16日

，我希望查看所有在2015年4月15日至2015年4月16日之间的预订.从视觉上看，这看起来像:

and I wish to view all reservations that are between 15/04/2015 to 16/04/2015. Visually, this might look like:

15 16 X________|_____|______X |X____|_____________X X______________|____X| | |

要获取这些日期之间的所有保留，我正在使用:

To get all the reservations that fall between these dates I am using:

public List<ReservationClientModel> GetReservationsByDateRange(int id, DateTime checkin, DateTime checkout) { var reservation = _repository.FindAllBy(x => (x.StartDate >= checkin && x.EndDate <= checkout) || (x.StartDate >= checkin && x.StartDate <= checkout) || (x.EndDate >= checkin && x.EndDate <= checkout)), y => y.RoomTypeNav) .ToList(); return Mapper.Map<List<ReservationClientModel>>(reservation); }

正在使用:

public IEnumerable<TEntity> FindAllBy(Expression<Func<TEntity, bool>> predicate, params Expression<Func<TEntity, object>>[] includes) { var set = _dbSet.AsQueryable(); set = includes.Aggregate(set, (current, include) => current.Include(include)); return set.Where(predicate); }

这只会返回最后两个保留，我相信这是因为它正在检查日期上的> = 和< = 而不是检查它是否在范围内.我知道使用SQL BETWEEN 运算符，但是我想知道是否有任何方法可以使用Linq表达式或在C#中执行此操作?理想情况下，我想将此操作作为EF查询的一部分，而不是返回所有保留，然后在此列表上执行操作.

This will only return the last two reservations though, and I believe this to be because it is checking for >= and <= on the dates, rather than checking that it falls within the range. I'm aware of using the SQL BETWEEN operator, but I was wondering if there is any way to do this using a Linq expression or from within C#? Ideally I would like to perform this as part of the EF Query as opposed to returning all reservations, then performing the operations on this list.

谢谢.

推荐答案

如果以下规则为真，则两个范围重叠:

Two ranges overlap if following rule is true:

(StartDate1 <= EndDate2) and (EndDate1 >= StartDate2)

通过将此规则应用于您的代码，您将得到:

By applying this rule to your code you get:

var reservation = _repository .FindAllBy(x => x.StartDate <= checkout && x.EndDate >= checkin, y => y.RoomTypeNav) .ToList();