Question

Create a new document

>>>Categories.insert({'test':'test'})
ObjectId('506b563df49a007f73000001')

Yep, created OK.

>>> Categories.find_one({'test':'test'})
{u'test': u'test', u'_id': ObjectId('506b4149f49a007cd0000000')}

Give it a new attribute ‘newAttr’ with value ‘hello’

>>> Categories.update({'_id':Categories.find_one({'test':'test'})['_id']},{'newAttr':'hello'})

Find the same document

>>> Categories.find_one({'test':'test'})
{u'test': u'test', u'_id': ObjectId('506b563df49a007f73000001')}

It hasn’t been updated??

Search for something containing the new attribute:

>>> Categories.find_one({'newAttr':'hello'})
{u'newAttr': u'hello', u'_id': ObjectId('506b4149f49a007cd0000000')}

Its created a separate document instead of updating the previous one??

Any idea how to correct this?

Answer 1

I don’t get the same you get when setting a new field, but I’m using this syntax:

cat.update({'_id':cat.find_one({'test':'test'})['_id']},{'$set':{'newattr':'hello'}})

See here for $set explanation.

>>> cat.find_one({'test':'test'})
{u'newattr': u'hello', u'test': u'test', u'_id': ObjectId('506b5d07594bc07d90000000')}