Limit the Result
To limit the result in MongoDB, we use the limit() method.
The limit() method takes one parameter, a number defining how many documents to return.
Consider you have a “customers” collection: Continue reading Python MongoDB Limit
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Python MongoDB Update
Update Collection
You can update a record, or document as it is called in MongoDB, by using the update_one() method.
The first parameter of the update_one() method is a query object defining which document to update.
Note: If the query finds more than one record, only the first occurrence is updated.
The second parameter is an object defining the new values of the document. Continue reading Python MongoDB Update
Python MongoDB Drop Collection
Delete Collection
You can delete a table, or collection as it is called in MongoDB, by using the drop() method.
Example
Delete the “customers” collection:
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
mycol.drop()
The drop() method returns true if the collection was dropped successfully, and false if the collection does not exist. Continue reading Python MongoDB Drop Collection
Python MongoDB Delete Document
Delete Document
To delete one document, we use the delete_one() method.
The first parameter of the delete_one() method is a query object defining which document to delete.
Note: If the query finds more than one document, only the first occurrence is deleted.
Python MongoDB Sort
Sort the Result
Use the sort() method to sort the result in ascending or descending order.
The sort() method takes one parameter for “fieldname” and one parameter for “direction” (ascending is the default direction).
Example
Sort the result alphabetically by name:
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
mydoc = mycol.find().sort("name")
for x in mydoc:
print(x)
Python MongoDB Query
Filter the Result
When finding documents in a collection, you can filter the result by using a query object.
The first argument of the find() method is a query object, and is used to limit the search.
Example
Find document(s) with the address “Park Lane 38”:
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
myquery = { "address": "Park Lane 38" }
mydoc = mycol.find(myquery)
for x in mydoc:
print(x)
Python MongoDB Find
In MongoDB we use the find() and find_one() methods to find data in a collection.
Just like the SELECT statement is used to find data in a table in a MySQL database.
Find One
To select data from a collection in MongoDB, we can use the find_one() method.
The find_one() method returns the first occurrence in the selection. Continue reading Python MongoDB Find
Python MongoDB Insert Document
A document in MongoDB is the same as a record in SQL databases.
Insert Into Collection
To insert a record, or document as it is called in MongoDB, into a collection, we use the insert_one() method.
The first parameter of the insert_one() method is a dictionary containing the name(s) and value(s) of each field in the document you want to insert. Continue reading Python MongoDB Insert Document
Python MongoDB Create Collection
A collection in MongoDB is the same as a table in SQL databases.
Creating a Collection
To create a collection in MongoDB, use database object and specify the name of the collection you want to create.
MongoDB will create the collection if it does not exist. Continue reading Python MongoDB Create Collection
Python MongoDB Create Database
Creating a Database
To create a database in MongoDB, start by creating a MongoClient object, then specify a connection URL with the correct ip address and the name of the database you want to create.
MongoDB will create the database if it does not exist, and make a connection to it.
Example
Create a database called “mydatabase”:
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
Important: In MongoDB, a database is not created until it gets content!
MongoDB waits until you have created a collection (table), with at least one document (record) before it actually creates the database (and collection). Continue reading Python MongoDB Create Database