multi document insert using mongoengine into mongodb

问题

In my flask app I am using MongoeEgine. I am trying to insert multiple documents into my places collection in my MongoDB.

My document class is defined as

class places(db.Document):

  name = db.StringField(max_length=200, required=True)    
  loc = db.GeoPointField(required=True)

  def __unicode__(self):
    return self.name

    a=[]
    a.append({"name" : 'test' , "loc":[-87,101]})
    a.append({"name" : 'test' , "loc":[-88,101]})
    x= places(a)

The last statement fails

x= places(a)
TypeError: __init__() takes exactly 1 argument (2 given)

I also tried to save this to my instance

places.insert(x)
places.save(x)

both fail. Please help.

回答1:

Places.objects.insert doesn't take a list of dictionaries it has to be Places instances. Normal operations would be to create individual instances of Places and save or insert eg:

Places(name="test", loc=[-87, 101]).save()
Places(name="test 2", loc=[-87, 101]).save()

However if you want to do a bulk insert you can pass a list of Places instances and call insert on the objects queryset eg:

Places.objects.insert([Places(name="test", loc=[-87, 101]), 
                       Places(name="test 2", loc=[-87, 101])])

回答2:

You try to initialize Document object for multiple documents at once. If you look at mongoengine's BaseDocument class, you'll see, that its __init__ method takes a dictionary of keyword arguments, which relate to fields of one single document.

If you want to do a bulk save, you have to make a list of places instances and pass it to insert() method.

a = []
a.append(places(**{"name": 'test', "loc": [-87,101]}))
a.append(places(**{"name": 'test', "loc": [-88,101]}))
x = places.objects.insert(a)

来源：https://stackoverflow.com/questions/15143482/multi-document-insert-using-mongoengine-into-mongodb

标签

python

mongodb

Flask

mongoengine