DateTime is not equal

Question

I have next code:

DateTime endTime = DateTime.Now.AddDays(30);
InsertIntoDatabase(endTime);
var row = Db.SelectRow("select endTime from MyTable Where @column=myval", columnValue);
Assert.Equal(row["endTime"], endTime); // This is false! Why?

Assert is false. And dates are different for some reason on milliseconds. Why???

endTime:

Date    {7/17/2015 12:00:00 AM} System.DateTime
        Day 17  int
        DayOfWeek   Friday  System.DayOfWeek
        DayOfYear   198 int
        Hour    1   int
        Kind    Unspecified System.DateTimeKind
        Millisecond 370 int
        Minute  21  int
        Month   7   int
        Second  27  int
        Ticks   635726928873700000  long
+       TimeOfDay   {01:21:27.3700000}  System.TimeSpan
        Year    2015    int

row["endTime"]:

Date    {7/17/2015 12:00:00 AM} System.DateTime
        Day 17  int
        DayOfWeek   Friday  System.DayOfWeek
        DayOfYear   198 int
        Hour    1   int
        Kind    Local   System.DateTimeKind
        Millisecond 371 int
        Minute  21  int
        Month   7   int
        Second  27  int
        Ticks   635726928873716049  long
+       TimeOfDay   {01:21:27.3716049}  System.TimeSpan
        Year    2015    int

WHY???

These two `DateTimes` are not equal. Look at the `Ticks` on both. — Yuval Itzchakov, Jun 17 '15 at 08:46
`DateTime` should be the same, are you sure you are using passed parameter and not something else in `InsertIntoDataBase`? — Sinatr, Jun 17 '15 at 08:46
In your Database, use a `Datetime2` (100ns precision) instead of a `Datetime` (3ms precision) => [ref](http://blogs.msdn.com/b/cdnsoldevs/archive/2011/06/22/why-you-should-never-use-datetime-again.aspx) — Sébastien Sevrin, Jun 17 '15 at 08:48

score 5 · Accepted Answer · edited May 23 '17 at 11:43

5

Maybe this (Difference between DateTime in c# and DateTime in SQL server) will help a little.

you can also use Datetime2 for SQL

edited May 23 '17 at 11:43

Community

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answered Jun 17 '15 at 08:52

sangram parmar

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This is the "real" answer, but maybe you could explain with a little more details – Sébastien Sevrin Jun 17 '15 at 08:53
yeah i can, but i think post by post, may be it will modify and that is why i point it to original post. :) – sangram parmar Jun 17 '15 at 09:22
Yes, but you should include some TL;DR at least. it shouldn't happen, but if the original answer is deleted, then this post would be useless – Sébastien Sevrin Jun 17 '15 at 09:28
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Vote to close as duplicate instead then, instead of linking to a post in an answer. – CodeCaster Jun 17 '15 at 09:28
Okay next time i will do that. – sangram parmar Jun 17 '15 at 09:30

score 0 · Answer 2 · answered Jun 17 '15 at 08:55

Looks like a rounding error to me, the DateTime has ticks of 635726928873700000 whereas the Row has 635726928873716049. This is probably due to differing levels of precision in the database vs DateTime.

The differences in ticks means they are different DateTimes.

DateTime is not equal

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