MongoDB is a cross-platform document-oriented database program and the most popular NoSQL database program. The term NoSQL means non-relational. MongoDB stores the data in the form of key-value pairs. It is an Open Source, Document Database which provides high performance and scalability along with data modeling and data management of huge sets of data in an enterprise application. MongoDB also provides the feature of Auto-Scaling. It uses JSON-like documents, which makes the database very flexible and scalable.
Finding data from the collection or the database
In MongoDB, there are 2 functions that are used to find the data from the collection or the database.
- find_one()
- find()
Find_one() Method
In MongoDB, to select data from the collection we use find_one() method. It returns the first occurred information in the selection and brings backs as an output. find_one() method accepts an optional parameter filter that specifies the query to be performed and returns the first occurrence of information from the database.
Example 1: Find the first document from the student’s a collection/database. Let’s suppose the database looks like as follows:
# Python program to demonstrate # find_one() import pymongo
mystudent = pymongo.MongoClient( 'localhost' , 27017 )
# Name of the database mydb = mystudent[ "gfg" ]
# Name of the collection mycol = mydb[ "names" ]
x = mycol.find_one()
print (x)
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Output :
Find()
find() method is used to select data from the database. It returns all the occurrences of the information stored in the collection. It has 2 types of parameters, The first parameter of the find() method is a query object. In the below example we will use an empty Query object, which will select all information from the collection. Note: It works the same as SELECT* without any parameter.
Example:
import pymongo
# establishing connection # to the database my_client = pymongo.MongoClient( 'localhost' , 27017 )
# Name of the database mydb = my_client[ "gfg" ]
# Name of the collection mynew = mydb[ "names" ]
for x in mycol.find():
print (x)
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Output :
Example: Return only the names and address, not the id:
Output: