Quering nested document query with Mongoengine - mongoengine

Question

I have been trying to Query some mongo instances variables with python and MongoEngine
I need to get all the Variable from every RegistroPozo in all the Collection.
Example code:
from mongoengine import *
class Variable(EmbeddedDocument):
mnem=StringField(required=True, max_length=200)
description=StringField(max_length=500)
unit=StringField( max_length=200,default='ppm')
alias=StringField( max_length=200) #,default=mnem
type=StringField( max_length=200,default='DEPENDANT')
class RegistroPozo(EmbeddedDocument):
fecha = DateTimeField()
filepath = StringField()
start = FloatField()
step = FloatField()
stop = FloatField()
variables = EmbeddedDocumentListField(Variable)
registros = ListField(DictField())
version_information_block = StringField(max_length=500)
well_information_block = StringField(max_length=500)
curve_information_block = StringField(max_length=500)
parameter_information_block = StringField(max_length=500)
other_block = StringField(max_length=500)
class Pozo(DynamicDocument):
uwi_pozo = StringField(required=True, max_length=200, primary_key=True)
nom_pozo = StringField(required=True, max_length=200)
prof_total = FloatField(required=True)
elev_terr = FloatField(required=True)
long_pozo = FloatField(required=True)
lat_pozo = FloatField(required=True)
coord_x_po = FloatField(required=True)
coord_y_po = FloatField(required=True)
registros_pozo=EmbeddedDocumentListField(RegistroPozo)
When I try to query I make a lot of loops, but I belive there is a better way to do it.
Something like:
variables_in_all_the_doc = Pozo.objects(Q(AdvanceQuery))

Answer 1

Pozo is a single document at mongo db level. Embeded document are just mongoengine constructs. So when you read Pozo objects, all embedded documents are also available in the same query (check with mongostat). Now iterating on this data is not a big concern. For advanced EmbeddedDocumentList queries please read the docs here.