Thanks Jim and Dave. Your suggestions give me something to think about
over the weekend.
But for now: startkey=burgundy
Stephan
On 12-04-27 03:38 PM, Dave Cottlehuber wrote:
On 28 April 2012 00:02, Jim Klo<[email protected]> wrote:
Okay, sorry, I missed the following days part. I'm not sure you can do
exactly what you want with a view only, but you probably want a list
function as well. the GeoCouch plugin would have been your best bet for
that... too bad...
You can still use the same type of view with keys like: [ date, eventid ],
then create a list function that uniques the eventid's; just do this any
time the eventid changes in the 'stream' you send the details once, - and if
you include with_docs; you could add the event details you want as well.
I do something very similar to this
here:
https://github.com/LearningRegistry/LearningRegistry/blob/master/data_services/standards-alignment-dct-conformsTo/lists/to-json.js#L18
Alternatively which is probably simpler:
If you can place some kind maximum fixed range requirement that's
reasonable, like I always want to show events within 5 days of the each
event... you could artificially emit extra date keys in your map... 5 days
before and 5 days after the event...
Say your event is for May 5, then you emit that event for every day in the
map from Apr 30 - May 10. You might have another event on the May 2, which
you emit dates from April 27 - May 7. If I search for May 2, event.. i'll
also get the may 5 event.
Then when you query the view with a simple reduce for a specific day... you
should get a list of all events within 5 days (10 day range)... of the date
specified. If you put some kind of larger limit on that like 14 days before
and after.. then post filter the result set using a list function into a
smaller range, to dates before or after, and etc.
- Jim
Jim Klo
Senior Software Engineer
Center for Software Engineering
SRI International
On Apr 27, 2012, at 2:06 PM, Stephan Bardubitzki wrote:
Thanks for your suggestions Jim.
Unfortunately, I have to count out GeoCouch for now and your first
suggestion doesn't satisfy my requirements. It would yield the events for a
particular day, but not for all following days, requiring more connections
to the db which I want to avoid for a mobile app.
Before posting I have tried a couple days to find a clean solution, but came
up with the start_date as key. It gives me all events, including past
events, and the hard work has to be done on client side.
My finding works, just have the feeling there is a more efficient way.
Stephan
On 12-04-27 11:38 AM, Jim Klo wrote:
There's a whole bunch of ways to do that... but here are 2:
1. create a map function that emits all the days of the event as keys - the
searching for any particular day would yield those events
2. use geocouch, store the start& end dates as a box, then you can use the
current date as a bbox to find all events that overlap. Using this method,
you'd want to store time as an integer value and not a string.
IMHO #2 is probably a cleaner approach, but requires GeoCouch.
- Jim
*
*
*
*Jim Klo*
Senior Software Engineer
Center for Software Engineering
SRI International
*
*
*
On Apr 27, 2012, at 11:19 AM, Stephan Bardubitzki wrote:
I have a database of events and since events can be multi-day events all
documents have a start_date and end_date. Now I want to get all events that
happen today and those that are starting in the coming days.
How should I determine if today is in the range of start_date and end_date?
To make things more complex an event can be assigned to one or more
categories such as sports, music etc. So the next task would be to get all
events of a certain category that happen today and in the coming days.
Since a db of events might be a common task I hope someone has already come
up with a solution.
Any advice would be greatly appreciated.
Stephan
Something like this maybe? Excuse egregrious errors in my pseudo-code:
doc: { "_id": "huge_partay_at_mah_place", "start": some_unix_date,
"duration": "3+days"}
map:
if (doc.start&& doc.duration)
{
for (i = doc.some_unix_date, i<= doc.duration*seconds_in_day, i+=
seconds_in_day)
{
emit(i, doc.event_name); // _id of doc is emitted "for free"
anyway in the view.
}
}
Basically you could then range query whatever dates you needed from
the client as startkey/endkey
using today and today + 5.
Very low load client side.
And as Jim says, some fancy include_docs would give you all the event
information. Although in this
case you'd get an identical copy per event, so perhaps some view
post-processing with a list would
clean it up.
Disclaimer: numerous grapes were harmed in the making of this email.
Some forward-looking statements may have been obscured through
burgundy-tinted lenses. YMMV. Caveat Bibendum.
A+
Dave
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