如何在跨越多天的时间安排中获取一天的结束时间

Question

假设我有一个名为Timing的表格：

显然，每一行代表特定日期的一个班次。

一天可以有多个不重叠的班次。

如果一个班次跨越第二天，它将在午夜分开，而后半部分的父 id 将与前半部分相同（如您在第 24 行和第 31 行中所见）

我想查询距离我的一天结束还有多少分钟（下一个关闭时间）。

例如，如果我在第 1 天，我的一天将在 第 2 天 - 凌晨 2:00 结束（因为轮班从 第 1 天 - 9:00 开始，并在第 2 天 - 2:00）结束。

如果有间隙（比如周末左右），我必须小心。请注意，没有第 3 天，因此下一个关闭时间将是第 4 天 - 23:15（前提是您在第 3 天）。

我主要是在寻找 Linq 查询（Timing.Where(x=> x.close_time

但我认为它可能非常复杂，所以我可以接受原始 SQL 查询。

编辑： 这是我到目前为止得到的：

    var localTime = DateTime.Now;
    var tomorrowDay = ((int)localTime.DayOfWeek + 7 + 1) % 7;

    Timing lastShift = Timings.Where(x =>
              ((int)x.DayOfWeek) == tomorrowDay && x.ParentId != null)
              .SingleOrDefault(); // Either it is tomorrow but starts today.

    if (lastShift != null)
    {
        return Convert.ToInt32((lastShift.CloseTime - localTime.TimeOfDay).TotalMinutes);
    }

    lastShift = Timings
              .Where(x => x.DayOfWeek == localTime.DayOfWeek && x.CloseTime >= localTime.TimeOfDay)
              .OrderByDescending(x => x.CloseTime)
              .Take(1).SingleOrDefault();

    return Convert.ToInt32((lastShift.CloseTime - localTime.TimeOfDay).TotalMinutes);

编辑：

感谢@Han，这是上面同一张表的列表：

    var Timings = new []
    {
        new Timing(22, (DayOfWeek)0, new TimeSpan(9,45,0), new TimeSpan(11, 15,  0),null),
        new Timing(23, (DayOfWeek)0, new TimeSpan(13,  0,  0), new TimeSpan( 15,  0,  0), null),
        new Timing(24, (DayOfWeek)1, new TimeSpan( 9,  0,  0), new TimeSpan(23, 59, 59), null),
        new Timing(31, (DayOfWeek)2, new TimeSpan( 0,  0,  0), new TimeSpan( 2,  0,  0), 24),
        new Timing(25, (DayOfWeek)2, new TimeSpan(10,  0,  0), new TimeSpan(12,  0,  0), null),
        new Timing(26, (DayOfWeek)2, new TimeSpan(15,  0,  0), new TimeSpan(17,  0,  0), null),
        new Timing(28, (DayOfWeek)4, new TimeSpan( 9, 45,  0), new TimeSpan(23, 15,  0), null),
        new Timing(29, (DayOfWeek)5, new TimeSpan( 9, 45,  0), new TimeSpan(23, 15,  0), null),
        new Timing(30, (DayOfWeek)6, new TimeSpan( 9, 45,  0), new TimeSpan(23, 15,  0), null),
    };

class Timing
{
    public int Id {get; set;}
    public DayOfWeek DayOfWeek {get; set;}
    public TimeSpan OpenTime {get; set;}
    public TimeSpan CloseTime {get; set;}
    public int? ParentId {get; set;}
    
    public Timing(int id, DayOfWeek dow, TimeSpan openTime, TimeSpan closeTime, int? parentId)
    {
        this.Id = id;
        this.DayOfWeek = dow;
        this.OpenTime = openTime;
        this.CloseTime = closeTime;
        this.ParentId = parentId;
    }
}

Answer 1

我建议离开自己加入你的桌子，以便在第二天获得关闭时间。我假设每一行都有零个或一个子行。我不使用表，而是使用数组，但查询应该是一样的。我在 LINQPad 中编写代码。

void Main()
{
    var Timings = new []
    {
        new Timing(22, 0, new DateTime(2021,  9, 12,  9, 45,  0), new DateTime(2021,  9, 12, 11, 15,  0), null),
        new Timing(23, 0, new DateTime(2021,  9, 12, 13,  0,  0), new DateTime(2021,  9, 12, 15,  0,  0), null),
        new Timing(24, 1, new DateTime(2021,  9, 13,  9,  0,  0), new DateTime(2021,  9, 13, 23, 59, 59), null),
        new Timing(31, 2, new DateTime(2021,  9, 14,  0,  0,  0), new DateTime(2021,  9, 14,  2,  0,  0), 24),
        new Timing(25, 2, new DateTime(2021,  9, 14, 10,  0,  0), new DateTime(2021,  9, 14, 12,  0,  0), null),
        new Timing(26, 2, new DateTime(2021,  9, 14, 15,  0,  0), new DateTime(2021,  9, 14, 17,  0,  0), null),
        new Timing(28, 4, new DateTime(2021,  9, 16,  9, 45,  0), new DateTime(2021,  9, 16, 23, 15,  0), null),
        new Timing(29, 5, new DateTime(2021,  9, 17,  9, 45,  0), new DateTime(2021,  9, 17, 23, 15,  0), null),
        new Timing(30, 6, new DateTime(2021,  9, 18,  9, 45,  0), new DateTime(2021,  9, 18, 23, 15,  0), null),
    };
    
    var timingGroupedWithChildren = (
        from t1 in Timings.Where(x => x.ParentId == null) // parent rows only
        join t2 in Timings.Where(x => x.ParentId != null) // childr rows only
            on t1.Id equals t2.ParentId // left join parent's Id with child's ParentId
            into nextDay
        select new {t1, nextDay})
        .Dump() //unremark this line to get show the result in LINQPad
        ;
}

class Timing
{
    public int Id {get; set;}
    public int DayOfWeek {get; set;}
    public DateTime OpenTime {get; set;}
    public DateTime CloseTime {get; set;}
    public int? ParentId {get; set;}
    
    public Timing(int id, int dow, DateTime openTime, DateTime closeTime, int? parentId)
    {
        this.Id = id;
        this.DayOfWeek = dow;
        this.OpenTime = openTime;
        this.CloseTime = closeTime;
        this.ParentId = parentId;
    }
}

timingGroupedWithChildren 如下所示：

请注意，只有 id = 24 有 nextDay，其他行没有 nextDay。有 8 个项目（显示在左上角），但仅详细显示了 Id 23 和 24（其他行折叠以节省空间，因为我的屏幕不够大）。

现在很容易得到第二天的关门时间。第一种方法是这样的。

void Main()
{
    var Timings = new []
    {
        new Timing(22, 0, new DateTime(2021,  9, 12,  9, 45,  0), new DateTime(2021,  9, 12, 11, 15,  0), null),
        new Timing(23, 0, new DateTime(2021,  9, 12, 13,  0,  0), new DateTime(2021,  9, 12, 15,  0,  0), null),
        new Timing(24, 1, new DateTime(2021,  9, 13,  9,  0,  0), new DateTime(2021,  9, 13, 23, 59, 59), null),
        new Timing(31, 2, new DateTime(2021,  9, 14,  0,  0,  0), new DateTime(2021,  9, 14,  2,  0,  0), 24),
        new Timing(25, 2, new DateTime(2021,  9, 14, 10,  0,  0), new DateTime(2021,  9, 14, 12,  0,  0), null),
        new Timing(26, 2, new DateTime(2021,  9, 14, 15,  0,  0), new DateTime(2021,  9, 14, 17,  0,  0), null),
        new Timing(28, 4, new DateTime(2021,  9, 16,  9, 45,  0), new DateTime(2021,  9, 16, 23, 15,  0), null),
        new Timing(29, 5, new DateTime(2021,  9, 17,  9, 45,  0), new DateTime(2021,  9, 17, 23, 15,  0), null),
        new Timing(30, 6, new DateTime(2021,  9, 18,  9, 45,  0), new DateTime(2021,  9, 18, 23, 15,  0), null),
    };
    
    var timingGroupedWithChildren = (
        from t1 in Timings.Where(x => x.ParentId == null) // parent rows only
        join t2 in Timings.Where(x => x.ParentId != null) // childr rows only
            on t1.Id equals t2.ParentId // left join parent's Id with child's ParentId
            into nextDay
        select new {
            t1.Id,
            t1.DayOfWeek,
            t1.OpenTime,
            // if current row's next day is null, then use current row's CloseTime
            // otherwise use next day's CloseTime
            CloseTime = nextDay.Where(x => x.ParentId == t1.Id).Count() == 0 ? t1.CloseTime : nextDay.Where(x => x.ParentId == t1.Id).Single().CloseTime
        })
        //.Dump() //unremark this line to get show the result in LINQPad
        ;
    
    var myShift = timingGroupedWithChildren.Where(x => x.Id == 24).Single();
    var myWorkingHours = (myShift.CloseTime - myShift.OpenTime).TotalHours;
    Console.WriteLine($"Working hours = {myWorkingHours}");
}

class Timing
{
    public int Id {get; set;}
    public int DayOfWeek {get; set;}
    public DateTime OpenTime {get; set;}
    public DateTime CloseTime {get; set;}
    public int? ParentId {get; set;}
    
    public Timing(int id, int dow, DateTime openTime, DateTime closeTime, int? parentId)
    {
        this.Id = id;
        this.DayOfWeek = dow;
        this.OpenTime = openTime;
        this.CloseTime = closeTime;
        this.ParentId = parentId;
    }
}

您可以在下面的图片中看到，如果当前行有孩子，我会替换结束日。但我不使用实际数据库测试此查询（我使用的是数组），我不喜欢调用 nextDay.Where(x => ...).Count() 两次，因为 LINQ 中的某些方法，例如. Count()，迭代所有行。它是用 Where(x => ...) 过滤的，但除非我看到调用此查询时执行的实际 SQL 语句，否则我什么也说不出来。如果在 SQL Management Studio 中打开 SQL Profiler 或使用 LINQPad SQL 翻译，则可以看到实际语句。该按钮位于图片顶部（结果 lambda 符号 SQL IL 树）。

另一种方法是在从 SQL 获取数据后获取子行并执行 Count()。

void Main()
{
    var Timings = new []
    {
        new Timing(22, 0, new DateTime(2021,  9, 12,  9, 45,  0), new DateTime(2021,  9, 12, 11, 15,  0), null),
        new Timing(23, 0, new DateTime(2021,  9, 12, 13,  0,  0), new DateTime(2021,  9, 12, 15,  0,  0), null),
        new Timing(24, 1, new DateTime(2021,  9, 13,  9,  0,  0), new DateTime(2021,  9, 13, 23, 59, 59), null),
        new Timing(31, 2, new DateTime(2021,  9, 14,  0,  0,  0), new DateTime(2021,  9, 14,  2,  0,  0), 24),
        new Timing(25, 2, new DateTime(2021,  9, 14, 10,  0,  0), new DateTime(2021,  9, 14, 12,  0,  0), null),
        new Timing(26, 2, new DateTime(2021,  9, 14, 15,  0,  0), new DateTime(2021,  9, 14, 17,  0,  0), null),
        new Timing(28, 4, new DateTime(2021,  9, 16,  9, 45,  0), new DateTime(2021,  9, 16, 23, 15,  0), null),
        new Timing(29, 5, new DateTime(2021,  9, 17,  9, 45,  0), new DateTime(2021,  9, 17, 23, 15,  0), null),
        new Timing(30, 6, new DateTime(2021,  9, 18,  9, 45,  0), new DateTime(2021,  9, 18, 23, 15,  0), null),
    };
    
    var timingGroupedWithChildren = (
        from t1 in Timings.Where(x => x.ParentId == null) // parent rows only
        join t2 in Timings.Where(x => x.ParentId != null) // childr rows only
            on t1.Id equals t2.ParentId // left join parent's Id with child's ParentId
            into nextDay
        select new {
            t1.Id,
            t1.DayOfWeek,
            t1.OpenTime,
            t1.CloseTime,
            NextDay = nextDay
        })
        //.Dump() //unremark this line to get show the result in LINQPad
        ;
        
    var myShift = timingGroupedWithChildren.Where(x => x.Id == 24).Single();
    var myWorkingHours = ((myShift.NextDay.Count() == 0 ? myShift.CloseTime : myShift.NextDay.Single().CloseTime) - myShift.OpenTime).TotalHours;
    Console.WriteLine($"Working hours = {myWorkingHours}");
}

class Timing
{
    public int Id {get; set;}
    public int DayOfWeek {get; set;}
    public DateTime OpenTime {get; set;}
    public DateTime CloseTime {get; set;}
    public int? ParentId {get; set;}
    
    public Timing(int id, int dow, DateTime openTime, DateTime closeTime, int? parentId)
    {
        this.Id = id;
        this.DayOfWeek = dow;
        this.OpenTime = openTime;
        this.CloseTime = closeTime;
        this.ParentId = parentId;
    }
}

您可以看到只有 Id = 24 的行具有 NextDay（如图片 #1）。