Extracting month from _id timestamp

[Voltron]

Happy new year to all!

I am having problems with a query. I would like to select all the
documents of a certain month usind the _id field. I am using Pymongo

I know that I can get a datetime object using the
"doc['_id'].generation_time" property, and the month in the datetime
object returned. How can construct a query to do this all at once?

Thanks

[Eli Jones]

Maybe the documentation will have some clues:

http://api.mongodb.org/python/1.9%2B/api/bson/objectid.html

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[Andreas Jung]

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If you need to query my creation month then create a dedicated
'created_month' property that you fill upon creation time.

- -aj
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[Voltron]

Thats what I was doing Andreas, I thought it was redundant since the
timestamp is stored in the ID. So its not worth the extra code, I
would just add month and "day_created" then. Thanks

On Jan 1, 6:11 pm, Andreas Jung <li...@zopyx.com> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Voltron wrote:
> > Happy new year to all!
>
> > I am having problems with a query. I would like to select all the
> > documents of a certain month usind the _id field. I am using Pymongo
>
> > I know that I can get a datetime object using the
> > "doc['_id'].generation_time" property, and the month in the datetime
> > object returned. How can construct a query to do this all at once?
>
> If you need to query my creation month then create a dedicated
> 'created_month' property that you fill upon creation time.
>
> - -aj
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.11 (Darwin)

> Comment: Using GnuPG with Mozilla -http://enigmail.mozdev.org/

>
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> =RZEg
> -----END PGP SIGNATURE-----
>

>  lists.vcf
> < 1KViewDownload

[Sam Millman]

The problem is that the timestamp is used as part of the calculation in the ID it is not actually in there, plus the ID is a hash (md5 I believe) so it is one way. Just add a ts time stamp using the drivers MongoDate object that way it is not redundant and can be used for more than just month.

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[Sam Millman]

Sorry for double post but:

"I know that I can get a datetime object using the
"doc['_id'].generation_time" property, and the month in the datetime
object returned. How can construct a query to do this all at once?"

Using the drivers mongo date object will allow you to do this, ie in php:

getCollection("users")->find(array("ts"=>new MognoDate(date(time()))))

Will find everything made today. I am sure you can do similar in pymongo

[Scott Hernandez]

You can easily get docs for a given month, for a given year, but not
the same month across (multiple) years with just an ObjectId.

On Sat, Jan 1, 2011 at 3:23 PM, Sam Millman <smil...@nhbs.co.uk> wrote:
> The problem is that the timestamp is used as part of the calculation in the
> ID it is not actually in there, plus the ID is a hash (md5 I believe) so it
> is one way. Just add a ts time stamp using the drivers MongoDate object that
> way it is not redundant and can be used for more than just month.

It is not hashed, and the date (in seconds) are the first 4 bytes.
http://mongodb.org/display/DOCS/Object+IDs

[Andrew Armstrong]

You are better off just recording this information explicitly.

On Jan 2, 10:34 am, Scott Hernandez <scotthernan...@gmail.com> wrote:
> You can easily get docs for a given month, for a given year, but not
> the same month across (multiple) years with just an ObjectId.
>

> On Sat, Jan 1, 2011 at 3:23 PM, Sam Millman <smill...@nhbs.co.uk> wrote:
> > The problem is that the timestamp is used as part of the calculation in the
> > ID it is not actually in there, plus the ID is a hash (md5 I believe) so it
> > is one way. Just add a ts time stamp using the drivers MongoDate object that
> > way it is not redundant and can be used for more than just month.
>

> It is not hashed, and the date (in seconds) are the first 4 bytes.http://mongodb.org/display/DOCS/Object+IDs

[Voltron]

Ok, just for future use, is there someone that can write this query in
Pymongo? I do not need the docs to the API, I know how to use the
datatime and objectid field to get the present time and othere
properties and I have been using a separate timestamp field in the
past without problems. I just wanted to reduce the data redundancy

I could, in anothere circumstance need to write something equally
complicated, I found nothing similarly advanced in the docs

Thanks