utc date time

sophia · March 1st, 2012, 03:31 AM

Thanks for quick reply.

Quote:

Does it work when you add a record in the table directly?

Yes it is working well, if I am inserting record directly in table.

Now what next?

sophia · March 2nd, 2012, 12:48 PM

Hi Imar,
what you were saying about constructor, how it will solve the problem, I do not want to use DateTime.UtcNow; in code behind

Thanks

Imar · March 3rd, 2012, 01:10 AM

If you set the date using a constructor, each time the time an instance of the class is created (by you, or by EF or by other code) the date gets a default UTC date. Then when the item is retrieved from the database the value gets overwritten.

This gives you an easy default value while you can still overwrite it.

Not sure why this doesn't work through the designer though.

Cheers,

Imar

sophia · March 3rd, 2012, 01:01 PM

Then would you write constructor as below

Code:

private Review()
{
   using(PlanetWroxEntities myEntities = new PlanetWroxEntities())
   {
       myEntities.CreateDateTime = DateTime.UtcNow;
    }
}

if this is so, then why not write this directly on save button click's code?

Quote:

Then when the item is retrieved from the database the value gets overwritten.

value gets overwritten when item is retrieved from database or written to database?

Many thanks

Imar · March 3rd, 2012, 02:53 PM

This code targets the entire context which doesn't make that much sense. Instead you want to target a single instance of a review. Just add something like this to your App_Code folder:

Code:

 
namespace PlanetWroxModel
{
  public partial class Review
  {
    public Review()
    {
      this.CreateDateTime = DateTime.UtcNow; 
    }
  }
}

This sets the CreateDateTime when a new instance is created.

Quote:

value gets overwritten when item is retrieved from database or written to database?

When retrieved from the database. If you query an old object from the database, you want its original CreateDateTime, not today's date.

Cheers,

Imar

sophia · March 5th, 2012, 11:38 AM

HI Imar,
is that complete code? how CreateDateTime can be found in that class?

Thanks

Imar · March 5th, 2012, 02:11 PM

Quote:

is that complete code?

Did you try it out? That would be the best way to get that question answered.

Note the partial keyword in the class declaration....

Cheers,

Imar

sophia · March 6th, 2012, 01:53 AM

Quote:

Did you try it out?

yes I tried it, but I used a different name for the class file being generated and then modified the code (class name and constructor name) inside that file manually, perhaps that's why it was not working.

Well, it is working now.

But here also we are using UTCNow somehow. why it is giving error if we insert date through function getutcdate().

Many thanks

Imar · March 6th, 2012, 07:24 AM

Not sure whay it doesn't work for you. Sounds like you didn't have StoreGeneratedPattern set to Computed....

Cheers,

Imar

sophia · March 6th, 2012, 10:14 AM

Quote:

Not sure whay it doesn't work for you

is it working on your side without writing constructor?

It is not working with StoreGeneratedPattern set to Computed too.