It's really like doing the query backwards, you're matching the keys you're
emitting to see if they exist in the array of keys you're supplying over the
querystring. Is there a way to get the key parameter (or any of the
parameters) from within a view? For instance...
function (doc) {
keys = params[key] //or some equivalient ??
Array.prototype.exists = function (x) {
for (var i = 0; i < this.length; i++) {
if (this[i] == x) return true;
}
return false;
}
if (doc.Type == 'Post') {
for (var i = 0; i < keys.length; i++) {
if (doc.tags.exists(keys[i])) {
emit(doc,null);
}
}
}
}
So you'd iterate over all of the keys you'd like to find and then with a little
prototyping you'd check to see if any of those keys existed within your field
that was an array. Talk me off the ledge here...
----- Original Message ----
From: Jan Lehnardt <[EMAIL PROTECTED]>
To: [email protected]
Sent: Thursday, July 3, 2008 9:03:46 AM
Subject: Re: Views using JSON Arrays
To pull that off you'd need to have every single combination
of tags in the index which I don't see happening. Maybe
with the reduce, I don't know.
what you can do is emit([tag1, tag2], null); and then query
with key=[tag1, tag2]]; and that would work the octopus
and hockey-case you line out here, but not in general.
Cheers
Jan
--
On Jul 3, 2008, at 15:52, Brad King wrote:
> Might be a hack, but would a collated view work for getting two
> arbitrary tags?
>
> function (doc) {
> for(var i=0; i<doc.Tags.length; i++)
> emit([doc.Tags[i], doc.Tags[i]], null);
>
> then you pass in ?key=["octopus","hockey"]
>
>
> On Thu, Jul 3, 2008 at 9:15 AM, Jan Lehnardt <[EMAIL PROTECTED]> wrote:
>>
>> On Jul 3, 2008, at 15:01, Bradford Winfrey wrote:
>>
>>> Hello everyone, been stalking the mailing list for a while and
>>> thought
>>> this might be worthy of a post as I was asked to solve it, yet, I
>>> couldn't!
>>>
>>> Let's take the classic blog example document with the following
>>> fields/values:
>>>
>>> "_id": "1f2fc3955b91aed5e7369f0b0ba8214e",
>>> "_rev": "1226709986",
>>> "Author": "Bradford",
>>> "Type": "Post",
>>> "Body": "Just mentioning this for a sample blog post.",
>>> "PostedDate": "2008-07-02T23:22:12-04:00",
>>> "Subject": "My Fine Blog Post",
>>> "Tags": ["octopus","hockey","squidward","bradford","recreation"]
>>>
>>> Next, I'd like to find each blog post that contains ANY of the
>>> following
>>> tags ["octopus","hockey"]. Now, generally speaking this isn't so
>>> bad. We
>>> could write a simple view:
>>> function (doc) {
>>> if (doc.Type == 'Post') {
>>> for (var i = 0;i < doc.tags.length; i++) {
>>> emit(doc.tags[i],doc);
>>> }
>>> }
>>> }
>>>
>>> We would get back each one of our tags as a key, yea? Only if we
>>> supplied
>>> one at a time. So how does one go about supplying a range, array
>>> (not sure
>>> what we'd call it here) of keys to be searched on?
>>> http://...?key=["octopus","hockey";] maybe? I'm unsure of the plan
>>> of
>>> attack for such a thing. Maybe I'm just going about it in the wrong
>>> direction. Any thoughts?
>>
>> have a look at the bottom of http://wiki.apache.org/couchdb/HttpViewApi
>> for the view query options. Specifically the startkey= and endkey=
>> ones.
>> Note that you only get consecutive ranges with that. To retrieve
>> arbitrary
>> tags, you'd need to run a query per tag with the key= option.
>>
>> Cheers
>> Jan
>> --
>>
>
