Prerequisites : MongoDB Python Basics We would first understand how to insert a document/entry in a collection of a database. Then we would work on how to update an existing document in MongoDB using pymongo library in python. The update commands helps us to update the query data inserted already in MongoDB database collection.
Insert data
We would first insert data in MongoDB.
- Step 1 – Establishing Connection: Port number Default: 27017
conn = MongoClient(‘localhost’, port-number)
- If using default port-number i.e. 27017. Alternate connection method:
conn = MongoClient()
- Step 2 – Create Database or Switch to Existing Database:
db = conn.dabasename
- Create a collection or Switch to existing collection:
collection = db.collection_name
- Step 3 – Insert : To Insert Data create a dictionary object and insert data in database. Method used to insert data:
insert_one() or insert_many()
- After insert to find the documents inside a collection we use find() command. The find() method issues a query to retrieve data from a collection in MongoDB. All queries in MongoDB have the scope of a single collection. Note : ‘_id’ is different for every entry in database collection. Let us understand insert of data with help on code:-
Python3
# Python code to illustrate# inserting data in MongoDBfrom pymongo import MongoClient try: conn = MongoClient() print("Connected successfully!!!")except: print("Could not connect to MongoDB") # databasedb = conn.database # Created or Switched to collection names: my_gfg_collectioncollection = db.my_gfg_collection emp_rec1 = { "name":"Mr.Geek", "eid":24, "location":"delhi" }emp_rec2 = { "name":"Mr.Shaurya", "eid":14, "location":"delhi" } # Insert Datarec_id1 = collection.insert_one(emp_rec1)rec_id2 = collection.insert_one(emp_rec2) print("Data inserted with record ids",rec_id1," ",rec_id2) # Printing the data insertedcursor = collection.find()for record in cursor: print(record) |
- Output:
Connected successfully!!!
Data inserted with record ids
{'_id': ObjectId('5a02227b37b8552becf5ed2a'),
'name': 'Mr.Geek', 'eid': 24, 'location': 'delhi'}
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name':
'Mr.Shaurya', 'eid': 14, 'location': 'delhi'}
Updating data in MongoDB
Methods used: update_one() and update_many() Parameters passed: + a filter document to match the documents to update + an update document to specify the modification to perform + an optional upsert parameter After inserting Data in MongoDB let’s Update the Data of employee with id:24
Python3
# Python code to illustrate# updating data in MongoDB# with Data of employee with id:24from pymongo import MongoClient try: conn = MongoClient() print("Connected successfully!!!")except: print("Could not connect to MongoDB") # databasedb = conn.database # Created or Switched to collection names: my_gfg_collectioncollection = db.my_gfg_collection # update all the employee data whose eid is 24result = collection.update_many( {"eid":24}, { "$set":{ "name":"Mr.GeeksforLazyroar" }, "$currentDate":{"lastModified":True} } ) print("Data updated with id",result) # Print the new recordcursor = collection.find()for record in cursor: print(record) |
Output:
Connected successfully!!!
Data updated with id
{'_id': ObjectId('5a02227b37b8552becf5ed2a'),
'name': 'Mr.GeeksforLazyroar', 'eid': 24, 'location':
'delhi', 'lastModified': datetime.datetime(2017, 11, 7, 21, 19, 9, 698000)}
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name':
'Mr.Shaurya', 'eid': 14, 'location': 'delhi'}
To find number of documents or entries in collection the are updated use.
print(result.matched_count)
Here output would be 1.
