Python – multi document insert using mongoengine into mongodb

flaskmongodbmongoenginepython

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.

Best Answer

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])])

Related Solutions

Mongodb – How to remove a field completely from a MongoDB document

Try this: If your collection was 'example'

db.example.update({}, {$unset: {words:1}}, false, true);

Refer this:

http://www.mongodb.org/display/DOCS/Updating#Updating-%24unset

UPDATE:

The above link no longer covers '$unset'ing. Be sure to add {multi: true} if you want to remove this field from all of the documents in the collection; otherwise, it will only remove it from the first document it finds that matches. See this for updated documentation:

https://docs.mongodb.com/manual/reference/operator/update/unset/

Example:

db.example.update({}, {$unset: {words:1}} , {multi: true});

Mongodb – Add new field to every document in a MongoDB collection

Same as the updating existing collection field, $set will add a new fields if the specified field does not exist.

Check out this example:

> db.foo.find()
> db.foo.insert({"test":"a"})
> db.foo.find()
{ "_id" : ObjectId("4e93037bbf6f1dd3a0a9541a"), "test" : "a" }
> item = db.foo.findOne()
{ "_id" : ObjectId("4e93037bbf6f1dd3a0a9541a"), "test" : "a" }
> db.foo.update({"_id" :ObjectId("4e93037bbf6f1dd3a0a9541a") },{$set : {"new_field":1}})
> db.foo.find()
{ "_id" : ObjectId("4e93037bbf6f1dd3a0a9541a"), "new_field" : 1, "test" : "a" }

EDIT:

In case you want to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents

db.your_collection.update(
  {},
  { $set: {"new_field": 1} },
  false,
  true
)

EDIT:

In the above example last 2 fields false, true specifies the upsert and multi flags.

Upsert: If set to true, creates a new document when no document matches the query criteria.

Multi: If set to true, updates multiple documents that meet the query criteria. If set to false, updates one document.

This is for Mongo versions prior to 2.2. For latest versions the query is changed a bit

db.your_collection.update({},
                          {$set : {"new_field":1}},
                          {upsert:false,
                          multi:true})

Best Answer

Related Solutions

Mongodb – How to remove a field completely from a MongoDB document

Mongodb – Add new field to every document in a MongoDB collection

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