How to use the "OR" operator?

[TheOnly92]

{$or: [{status: 1}, {status: 0}]}, I write this way in JSON, but how
do I write it in bson?

I can't bson.M{"$or": bson.M{bson.M{"status":0},
bson.M{"status":nil}}}, right? It gives me: missing key in map literal

I can't use bson.M{"$or": bson.D{{"status",1}, {"status",nil}}} as
well, crashes with: $or requires nonempty array

[Fabian]

I have quite the same problem - how to use conditional operators.
If I've not missed something, this is not possible at the moment - so
I can't even filter my results by the existance of a specific field.
Of course one could do these things in a For-Func but before I do that
I better ask whether I've just failed to see the right function.

For the case that I'm right - would it be possible to call
Collection.Find() with json data as a string? This would make things a
lot easier and clearer for complex queries.

[Gustavo Niemeyer]

Hi Fabian,

> I have quite the same problem - how to use conditional operators.
> If I've not missed something, this is not possible at the moment - so

I believe gobson is able to represent pretty much anything you can do
with the bson standard, so any query you find floating around you can
execute using gobson.

--
Gustavo Niemeyer
http://niemeyer.net
http://niemeyer.net/plus
http://niemeyer.net/twitter
http://niemeyer.net/blog

-- I never filed a patent.

[Gustavo Niemeyer]

Hey there,

You have to reproduce the same query you have in JSON.  If JSON has a list, you'll need a list in bson as well, which is represented by slices in Go, as usual.  If you want a generic list for querying purposes, you can easily define a type like this locally:

type L []interface{}

[Fabian Reinartz]

Okay, it finally worked. No idea what went wrong before. 

Thanks for your fast help :)

[Jon Conradt]

Would you mind posting the resulting code?  I am running into the same problem.  Basically, I want to have $or with a list of potential values for the same key and I can't seem to get the syntax right.

Thanks!

Jon

[Jordan Orelli]

well what you have to remember is that you're writing in native Go types, and your goal is to have it serialize to the $or semantics.  There are multiple ways to arrive at such a result, but the one I common use is this:

bson.M{"$or": []bson.M{bson.M{"somekey": "someval"}, bson.M{"otherkey": "otherval"}},

the value of an "$or" is an array of selectors.

Likewise, the $in modifier is used like this:

bson.M{"first_name": bson.M{"$in": []string{"Stanley", "Herbert", "Alfred"}}}

(based on your stated goal, it sounds like you're actually looking for the $in modifier)

[Jon Conradt]

Thanks!  My practice project has me learning Go and Mongo at the same time.  The pointer to look at $in is really helpful.

It is always frustrating when you read through a thread as two people are working on the same problem you are facing and the last message just says, "Got it to work!"  Having the working snippet of code is a big help.  :)

Jon

[서원기 차장]

hi  i am wonki 

programing in korea

 

i send code source  

mongo write protocol use delphi .. BSON ..

but query  "or" operation not use ..

 

I want code  "or" query code samiple ....

ex)  {$or:[{DKEY:{$in:['1869','1870']}},{STATECD:{$in:['0102','0104']}}]}  -> BSON Format (  BSON([ 'DKEY', BSON(acdkey) ]); )..

 

Tanks!  Tanks!  ^^

2012/5/30 Jon Conradt <j...@theconradts.com>

[Gustavo Niemeyer]

Hello there,

Sorry, but I can't really follow what you are asking about or trying to achieve.

If you want a code sample for an $or query, Jordan already sent one to
this thread, and pretty much any query you find in the actual MongoDB
documentation can also be used with mgo by translating the curly
braces to the bson.M{} syntax.

I hope this helps.

gustavo @ http://niemeyer.net