find() include and exclude keys in same time

[michael Baarz]

Hello,

i have found the following info in the Definitive MongoDB Guide:


You can also use this second parameter to exclude specific key/value
pairs from the
results of a query. For instance, you may have documents with a
variety of keys, and
the only thing you know is that you never want to return the
"fatal_weakness" key:
> db.users.find({}, {"fatal_weakness" : 0})
This can even prevent "_id" from being returned:
> db.users.find({}, {"username" : 1, "_id" : 0})
{
"username" : "joe",
}


This is very nice i dont wanna the _id value. Now do something similar
in my mongodb:


> db.custs_struct.find({pid:4},{cid:1, "_id":0})
error: {
"$err" : "You cannot currently mix including and excluding fields.
Contact us if this is an issue."
}
>

Is it a bug, or a feature? How to exclude the _id value now from the
return values?

[Eliot Horowitz]

What version are you on?
I think that was a change for 1.6

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[Justin Dearing]

I just discovered this now and its kinda annoying for me. I want to
exclude dates from this subcollections:

> db.events.findOne(null, {_id:1, Name:1, "Locations":1 })
{
"_id" : ObjectId("4cbc7344b4a5ef111c1a3c6a"),
"Name" : "Bar Crawl",
"Locations" : {
"_t" :
"System.Collections.Generic.List`1[[Wunderman.EventRSVPSite.BusinessObjects.EventLocation,
EventRSVPSite.BusinessObjects]]",
"v" : [
{
"_id" :
ObjectId("4cbc7345b4a5ef111c1a3c6b"),
"Name" : "McSorley's Olde Ale House",
"Address1" : "15 East 7th Street",
"Address2" : null,
"City" : "New York",
"State" : "NY",
"Zip" : "10003",
"Capacity" : 0,
"Dates" : {
"_t" :
"System.Collections.Generic.List`1[[Wunderman.EventRSVPSite.BusinessObjects.EventDate,
EventRSVPSite.BusinessObjects]]",
"v" : [ ]
}
},
{
"_id" :
ObjectId("4cbc7345b4a5ef111c1a3c6c"),
"Name" : "O'Keefe's Bar & Grill",
"Address1" : "62 Court St",
"Address2" : null,
"City" : "Brooklyn",
"State" : "NY",
"Zip" : "11201",
"Capacity" : 0,
"Dates" : {
"_t" :
"System.Collections.Generic.List`1[[Wunderman.EventRSVPSite.BusinessObjects.EventDate,
EventRSVPSite.BusinessObjects]]",
"v" : [ ]
}
}
]
}
}


So I tried this:

> db.events.findOne(null, {_id:1, Name:1, "Locations":1, "Locations.v.Dates": 0})
Mon Oct 18 12:23:27 uncaught exception: error {

"$err" : "You cannot currently mix including and excluding

fields. Contact us if this is an issue.",
"code" : 10053
}

Now I get the same results from:
db.events.findOne(null, {_id:1, Name:1, "Locations._t":1,
"Locations.v.Name":1, "Locations.v.Address1":1, "Locations.v.Address2":
1, "Locations.v.City":1, "Locations.v.State":1,"Locations.v.Zip":1 })

However, if the first form worked, it would be more readable.

Justin

On Oct 13, 9:43 am, Eliot Horowitz <eliothorow...@gmail.com> wrote:
> What version are you on?
> I think that was a change for 1.6
>
>
>
> On Wed, Oct 13, 2010 at 8:57 AM, michael Baarz <mba...@gmail.com> wrote:
> > Hello,
>
> > i have found the following info in the Definitive MongoDB Guide:
>

> > You can also use this second parameter toexcludespecific key/value

> > pairs from the
> > results of a query. For instance, you may have documents with a

> > variety ofkeys, and

> > the only thing you know is that you never want to return the
> > "fatal_weakness" key:
> >> db.users.find({}, {"fatal_weakness" : 0})
> > This can even prevent "_id" from being returned:
> >> db.users.find({}, {"username" : 1, "_id" : 0})
> > {
> > "username" : "joe",
> > }
>
> > This is very nice i dont wanna the _id value. Now do something similar
> > in my mongodb:
>
> >> db.custs_struct.find({pid:4},{cid:1, "_id":0})
> > error: {
> >        "$err" : "You cannot currently mix including and excluding fields.
> > Contact us if this is an issue."
> > }
>

> > Is it a bug, or a feature? How toexcludethe _id value now from the

[Kristina Chodorow]

This works in 1.6.3 & the 1.7 branch, which version are you using?

[Justin Dearing]

1.6.3, official mongodb.org binaries, not a personal build.

From the log:

Mon Oct 18 09:31:23 MongoDB starting : pid=1932 port=27017 dbpath=/data/db/ 32-bit

Mon Oct 18 09:31:23 db version v1.6.3, pdfile version 4.5

Mon Oct 18 09:31:23 git version: 278bd2ac2f2efbee556f32c13c1b6803224d1c01

Mon Oct 18 09:31:23 sys info: windows (5, 1, 2600, 2, 'Service Pack 3') BOOST_LIB_VERSION=1_35

Mon Oct 18 09:31:24 [initandlisten] waiting for connections on port 27017

Mon Oct 18 09:31:24 [websvr] web admin interface listening on port 28017

Mon Oct 18 11:21:12 [initandlisten] connection accepted from 127.0.0.1:21715 #1

Mon Oct 18 11:21:12 [conn1] query admin.$cmd ntoreturn:1 command: { ismaster: 1 } reslen:64 349ms

[Kristina Chodorow]

Oh, never mind.  Excluding the _id field works, but other stuff doesn't.  Agreed it would be easier, I guess this is the case to watch/vote for: http://jira.mongodb.org/browse/SERVER-391.

[Justin Dearing]

I didn't find that when checked JIRA before, so I added a comment with the error message. Now you can find it by searching jira for "You cannot currently mix including and excluding fields. Contact us if this is an issue."

Justin