Open rozza opened 12 years ago
Ross,
Thanks for confirming this as a limitation. For the moment I'll use raw queries.
One idea would be to follow the Django example of using operators regex and iregex, which don't take pre-compiled expressions.
Alec
Good call - as you dont actually need to provide a regex to use the $regex operator.
Did this ever got implemented?
This is an issue for us. Don't see a way to work around it, even with raw queries. Was there a resolution?
I have same issue, here is a sample code:
from mongoengine.connection import register_connection, DEFAULT_CONNECTION_NAME
from mongoengine import Document, StringField
from mongoengine.queryset import Q
import re
class Sample(Document):
name = StringField(max_length=200, required=True)
family = StringField(max_length=200, required=True)
def __unicode__(self):
return '{}.{}'.format(self.name, self.family)
print(mongoengine.VERSION)
# (0, 8, 7)
register_connection(DEFAULT_CONNECTION_NAME, 'test')
Sample.drop_collection()
s = Sample(name='omid', family='raha')
s.save()
print(Sample.objects.all())
# [<Sample: omid.raha>]
r = re.compile('omid', 1)
q = Q()
q.query["name"] = r
print(Sample.objects.filter(q))
# [<Sample: omid.raha>]
print(Sample.objects.filter(q, family='raha'))
# raise `TypeError: cannot deepcopy this pattern object`
Is this issue fixed ? If not, Experts - please fix it !! :)
Here is how to use raw query:
mongoengine.Q(__raw__={'email': {'$regex': email_pattern}})
But it doesn't work with negation: https://jira.mongodb.org/browse/SERVER-13779
Hi guys,
I ran into the same issue and unfortunately I can't use {'$regex': <pattern>}
because as @mindojo-victor said, you cannot negate the expression (required by my use case).
After multiple workaround attempts I found a pretty decent solution thanks to the bson.regex.Regex
class ans its Regex.from_native
method:
So in @omidraha's example, you'd use it like:
from bson.regex import Regex
r = Regex.from_native(re.compile('omid', 1))
q = Q()
q.query["name"] = r
Hope this fixes your issue as it did for me :-)
@oblivionguns Does your approach work with regex negation? Because it's MongoDB server limitation.
Yes it does because it's equivalent to (in mongo shell):
{"name": {$not: /exemple/}}
or in Python to:
query["name"] = Regex.from_native(re.compile('omid', 1))
# or
query["name"] = re.compile('omid', 1) # which should work with pymongo directy
This allows to negate a regex (which you can't with the $regex
operator as you pointed out).
Wow! Looks like it's working:
In [1]: import mongoengine as me
In [2]: import bson.regex
In [3]: from *** import User
In [4]: User.objects.count()
Out[4]: 2548
In [5]: User.objects(me.Q(email={'$not': bson.regex.Regex('example.com$', 'i')})).count()
Out[5]: 2533
Thank you!
Strange that this doesn't work:
In [8]: User.objects(me.Q(email__ne=bson.regex.Regex('example.com$', 'i'))).count()
...
OperationFailure: command SON([('count', u'user'), ('fields', None), ('query', {'email': {'$ne': Regex('example.com$', 2)}})]) on namespace brain2.$cmd failed: Can't have regex as arg to $ne.
Yeah that is a MongoDB limitation. Negating regex must be done with $not it seems.
Moreover, that would have a rather stranger meaning : "not equal to email__eq
? (Wouldn't make more sense in my opinion :-p)
Here's what I'm trying to do. Using a regex causes "TypeError: cannot deepcopy this pattern object"
import re MyDocument.objects(domain='amazon.com') if subject: filter(subject=re.compile('.*'))
Any suggestions? I realize there are some ways around this (i.e. build a dict and then do MyDocument.objects(**kwargs)), but I also need to include an OR expression:
from mongoengine.queryset import Q MyDocument.objects( (Q(subject=re.compile('text.'))| Q(subject=re.compile('other.')) & Q(domain='amazon.com')))
Which seems to require a deepcopy as it throws the same error.