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

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)

Advanced Query

To make advanced queries you can use modifiers as values in the query object.

E.g. to find the documents where the "address" field starts with the letter "S" or higher (alphabetically), use the greater than modifier: {"$gt": "S"}:

Example

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myquery = { "address": { "$gt": "S" } }

mydoc = mycol.find(myquery)

for x in mydoc:
  print(x)

Filter With Regular Expressions

You can also use regular expressions as a modifier.

Note: Regular expressions can only be used to query strings.

To find only the documents where the "address" field starts with the letter "S", use the regular expression {"$regex": "^S"}:

Example

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myquery = { "address": { "$regex": "^S" } }

mydoc = mycol.find(myquery)

for x in mydoc:
  print(x)