Function to create 24h periods timestamps? c#

I have database where data is stored along timestamp entries, that are keys.

i need a function that can transform a date like DateTime.Now into a timestamp interval representing, for today as example, Aug 3开发者_如何学C0th 00:00:00h to Aug 30th 23:59:59h.

How could i write that function?

What i want is to do something like

select all from table where timestamp is between a and b.(those and b values would represent the initial and terminal timestamps for a day.)

I did not create the db, i cannot modify it, i can only query it.

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This will return a tuple representing the interval you probably want:

Tuple<DateTime,DateTime> GetDateInterval(DateTime datetime) {
    var start = datetime.Date;
    var end = start.AddDays(1).AddTicks(-1);
    return new Tuple<DateTime, DateTime>(start, end);
}

Usage:

var interval = GetDateInterval(DateTime.Now);
Console.WriteLine(interval.Item1);
Console.WriteLine(interval.Item2);

Output:

30.08.2011 0:00:00
30.08.2011 23:59:59

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Maybe DateTime.Now.TimeOfDay.Ticks is what you are looking for.

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Hard to tell what you want, but here is a way to get the interval:

var start = DateTime.Today;
var end = start.AddDays(1).AddSeconds(-1);

It's hard to answer how you should store the values in the DB since you haven't provided enough details about the table layout.

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If you have the scope of a day, you can calculate the ticks withing the day:

// ----------------------------------------------------------------------
public long GetTicksOfDay( DateTime moment )
{
  return moment.Subtract( moment.Date ).Ticks;
} // GetTicksOfDay

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I think what you need is a TimeSpan.

You can just substract one DateTime from another, and the result will be a TimeSpan of the difference.

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I guess you might try using a structure as a TimeInterval:

public struct TimeInterval
{
    private readonly DateTime _startTime;
    private readonly DateTime _endTime;

    public DateTime StartTime { get { return _startTime; } }
    public DateTime EndTime { get { return _endTime; } }

    public TimeInterval(DateTime now)
    {
        _startTime = now.Date;
        _endTime = now.Date.AddDays(1).AddTicks(-1);
    }
}

You can call it:

TimeInterval day = new TimeInterval(DateTime.Now);