PyMongo is a Python driver for working with MongoDB and allows developers to connect to MongoDB from Python, interface with MongoDB databases and collections, and perform common operations like inserting, finding, updating, and deleting documents. It maps common SQL concepts like databases, tables, and rows to MongoDB concepts like databases, collections, and BSON documents. The document provides examples of basic PyMongo operations for connecting to a MongoDB server, getting and working with databases and collections, and performing CRUD operations on documents.

1. PyMongo for the Clueless
klrkdekira@gmail.com

2. http://www.python.org

3. http://www.mongodb.org/

4. ● json-like (bson) document store
● full index support
● replication and high availability
● auto sharding
● querying
● fast in-place update
● map/reduce
● GridFS

5. SQL to Mongo Mapping
MySQL Term MongoTerm
database database
table collection
index index
row BSON document
column BSON field
join embedding and linking
primary key _id field

6. PyMongo
The romantic story of
and

7. Connection Part 1
>>> import pymongo
>>> conn = pymongo.Connection()
is equivalent to
>>> conn = pymongo.Connection('localhost', 27017)
Getting the database
>>> db = conn.testdb
is equivalent to
>>> db = conn['testdb']

8. Basic Part 2
Getting the collection
>>> collection = db.test_collection
also is equivalent to
>>> collection = db['test_collection']
Make it understood from now

9. Insert New Document(s)
>>> dummy = db['dummy']
>>> dummy.insert({'key': 'a',
'value': 1})
ObjectId('4e7c50eb059bf61d2f000000')
Multiple insert
>>> docs = [{'key':'b', 'value':2},
{'key':'c', 'value':3}]
>>> dummy.insert(docs)
[ObjectId('4e7c552a059bf61d2f000002'), ObjectId
('4e7c552a059bf61d2f000003')]

10. Find Part 1
>>> dummy.find_one()
{u'_id': ObjectId('4e7c50eb059bf61d2f000000'), u'key': u'a', u'value': 1}
>>> dummy.find()
<pymongo.cursor.Cursor object at 0x2810ed0>
>>> for d in dummy.find():
print d
{u'_id': ObjectId('4e7c50eb059bf61d2f000000'), u'key': u'a', u'value': 1}
{u'_id': ObjectId('4e7c5544059bf61d2f000004'), u'key': u'b',
u'value': 2}
{u'_id': ObjectId('4e7c5544059bf61d2f000005'), u'key': u'c',
u'value': 3}

11. Find Part 2
>>> dummy.find_one({'key':'a'})
{u'_id': ObjectId('4e7c50eb059bf61d2f000000'), u'key': u'a', u'value': 1}
Query by ObjectId
>>> from bson.objectid import ObjectId
>>> dummy.find_one({'_id':ObjectId('4e7c50eb059bf61d2f000000')})
{u'_id': ObjectId('4e7c50eb059bf61d2f000000'), u'key': u'a', u'value': 1}
Same goes with find.

12. Update
>>> dummy.update({'key':'a'},
{'value':2})
Update multiple document, destructive
>>> dummy.update({'key':'a'},
{'value':2},
multi=True)
Just to overwrite attributes
>>> dummy.update({'key':'a'},
{'$set':{'value':2}})

13. Delete
Remove multiple file
>>> dummy.remove({'key':'a'})
Remove by ObjectId
>>> dummy.remove({'_id':ObjectId('4e7c50eb059bf61d2f000000')})

14. Stored JS
>>> db.system.js.add = "function (x, y) { return x + y; }"
>>> db.system.js.add(1, 2)
3.0
>>> del db.system.js.add

15. QUESTION ?