DateTime comparison without time part?

Question

I wrote this code. But I want to ignore time, I want to compare only day.

from s in sayac_okumalari
where s.okuma_tarihi == startDate && s.sayac_id == sayac_id
group s by new { date = new DateTime(((DateTime)s.okuma_tarihi).Year, ((DateTime)s.okuma_tarihi).Month, ((DateTime)s.okuma_tarihi).Day, ((DateTime)s.okuma_tarihi).Hour, 1, 1) } into g
select new
{
     okuma_tarihi = g.Key.date,
     T1 = g.Sum(x => x.toplam_kullanim_T1),
     T2 = g.Sum(x => x.toplam_kullanim_T2),
     T3 = g.Sum(x => x.toplam_kullanim_T3)
};

for example:

25.02.1987 == 25.02.1987

Manton

Possible duplicate of How to compare only Date without Time in DateTime types in C#? – Soutine

Answer 1

use s.okuma_tarihi.Value.Date == startDate.Date. This should allow you to compare only the Date component.

Update From the discussion in comments looks like the user is using NullableType. Hence updated the solution for NullableType.

Hermie

's.okuma_tarihi' does not contain a definition for 'Date' – Sulphuric

Looks like from your code snippet, you need to typecast s.okuma_tarihi to DateTime – Hermie

s.okuma_tarihi.Value.Date == startDate.Date is working.If edit your solution I will mark it. Thanks. – Sulphuric

((DateTime)s.okuma_tarihi).Date use only calling, assigment. – Sulphuric

Updated. But, looks like you are using Nullable type. You may need to ensure that Nullable type has value before performing action. – Hermie

This is usefull knowledge for me. Thanks a lot. – Sulphuric

Answer 2

Use Date property of DateTime. For ex,

var date= DateTime.Now.Date;

Influence

Answer 3

Because you could convert s.okuma_tarihi to DateTime, I think you could do:

var sonuc = from s in sayac_okumalari
        where (DateTime)s.okuma_tarihi.Date == startDate.Date && s.sayac_id == sayac_id
        group s by new { date = new DateTime(((DateTime)s.okuma_tarihi).Year, ((DateTime)s.okuma_tarihi).Month, ((DateTime)s.okuma_tarihi).Day, ((DateTime)s.okuma_tarihi).Hour, 1, 1) } into g
        select new
        {
             okuma_tarihi = g.Key.date,
             T1 = g.Sum(x => x.toplam_kullanim_T1),
             T2 = g.Sum(x => x.toplam_kullanim_T2),
             T3 = g.Sum(x => x.toplam_kullanim_T3)
        };

Hope it helps.

Pinhead

Answer 4

Try using the Date property on the DateTime Object will be a good a simple solution.

string AdmissionDate = "10/15/2017" // mm/dd/yyyy
string DepartureDate = "10/14/2017" // mm/dd/yyyy

if (Convert.ToDateTime(AdmissionDate).Date > Convert.ToDateTime(DepartureDate).Date)
{
    // Validation: Admission Date can not be greater than Departure Date... 
}

Disconsider

Answer 5

Try this...

        try
        {
         DateTime Date1= DateTime.ParseExact(txtBox1.Text,"dd/MM/yyyy",null);
         DateTime Date2 = DateTime.ParseExact(txtBox2.Text, "dd/MM/yyyy", null);

          if (Date1 > Date2) 
          {
           //........
          }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

Psychometry