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).
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)
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.
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)
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.
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
A document in MongoDB is the same as a record in SQL databases.
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
A collection in MongoDB is the same as a table in SQL databases.
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
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.
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
Python can be used in database applications.
One of the most popular NoSQL database is MongoDB.
MongoDB stores data in JSON-like documents, which makes the database very flexible and scalable.
To be able to experiment with the code examples in this tutorial, you will need access to a MongoDB database.
You can download a free MongoDB database at
https://www.mongodb.com.
Or get started right away with a MongoDB cloud service at
https://www.mongodb.com/cloud/atlas.
You can combine rows from two or more tables, based on a related column between them, by using a JOIN statement.
Consider you have a “users” table and a “products” table:
{ id: 1, name: 'John', fav: 154},
{ id: 2, name: 'Peter', fav: 154},
{ id: 3, name: 'Amy', fav: 155},
{ id: 4, name: 'Hannah', fav:},
{ id: 5, name: 'Michael', fav:}
{ id: 154, name: 'Chocolate Heaven' },
{ id: 155, name: 'Tasty Lemons' },
{ id: 156, name: 'Vanilla Dreams' }
These two tables can be combined by using users’ fav field and products’ id field. Continue reading Python MySQL Join
You can limit the number of records returned from the query, by using the “LIMIT” statement:
Select the 5 first records in the “customers” table:
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="yourusername",
password="yourpassword",
database="mydatabase"
)
mycursor = mydb.cursor()
mycursor.execute("SELECT * FROM customers LIMIT 5")
myresult = mycursor.fetchall()
for x in myresult:
print(x)
You can update existing records in a table by using the “UPDATE” statement:
Overwrite the address column from “Valley 345” to “Canyon 123”:
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="yourusername",
password="yourpassword",
database="mydatabase"
)
mycursor = mydb.cursor()
sql = "UPDATE customers SET address = 'Canyon 123' WHERE address = 'Valley 345'"
mycursor.execute(sql)
mydb.commit()
print(mycursor.rowcount, "record(s) affected")
Important!: Notice the statement: mydb.commit(). It is required to make the changes, otherwise no changes are made to the table.
Notice the WHERE clause in the UPDATE syntax: The WHERE clause specifies which record or records that should be updated. If you omit the WHERE clause, all records will be updated!