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While retrieving using find() method, you can filter the documents using the query object. You can pass the query specifying the condition for the required documents as a parameter to this method.
Operators
Following is the list of operators used in the queries in MongoDB.
| Operation | Syntax | Example |
|---|---|---|
| Equality | {“key” : “value”} | db.mycol.find({“by”:”tutorials point”}) |
| Less Than | {“key” :{$lt:”value”}} | db.mycol.find({“likes”:{$lt:50}}) |
| Less Than Equals | {“key” :{$lte:”value”}} | db.mycol.find({“likes”:{$lte:50}}) |
| Greater Than | {“key” :{$gt:”value”}} | db.mycol.find({“likes”:{$gt:50}}) |
| Greater Than Equals | {“key” {$gte:”value”}} | db.mycol.find({“likes”:{$gte:50}}) |
| Not Equals | {“key”:{$ne: “value”}} | db.mycol.find({“likes”:{$ne:50}}) |
Example1
Following example retrieves the document in a collection whose name is sarmista.
from pymongo import MongoClient
#Creating a pymongo client
client = MongoClient(''localhost'', 27017)
#Getting the database instance
db = client[''sdsegf'']
#Creating a collection
coll = db[''example'']
#Inserting document into a collection
data = [
{"_id": "1001", "name": "Ram", "age": "26", "city": "Hyderabad"},
{"_id": "1002", "name": "Rahim", "age": "27", "city": "Bangalore"},
{"_id": "1003", "name": "Robert", "age": "28", "city": "Mumbai"},
{"_id": "1004", "name": "Romeo", "age": "25", "city": "Pune"},
{"_id": "1005", "name": "Sarmista", "age": "23", "city": "Delhi"},
{"_id": "1006", "name": "Rasajna", "age": "26", "city": "Chennai"}
]
res = coll.insert_many(data)
print("Data inserted ......")
#Retrieving data
print("Documents in the collection: ")
for doc1 in coll.find({"name":"Sarmista"}):
print(doc1)
Output
Data inserted ......
Documents in the collection:
{''_id'': ''1005'', ''name'': ''Sarmista'', ''age'': ''23'', ''city'': ''Delhi''}
Example2
Following example retrieves the document in a collection whose age value is greater than 26.
from pymongo import MongoClient
#Creating a pymongo client
client = MongoClient(''localhost'', 27017)
#Getting the database instance
db = client[''ghhj'']
#Creating a collection
coll = db[''example'']
#Inserting document into a collection
data = [
{"_id": "1001", "name": "Ram", "age": "26", "city": "Hyderabad"},
{"_id": "1002", "name": "Rahim", "age": "27", "city": "Bangalore"},
{"_id": "1003", "name": "Robert", "age": "28", "city": "Mumbai"},
{"_id": "1004", "name": "Romeo", "age": "25", "city": "Pune"},
{"_id": "1005", "name": "Sarmista", "age": "23", "city": "Delhi"},
{"_id": "1006", "name": "Rasajna", "age": "26", "city": "Chennai"}
]
res = coll.insert_many(data)
print("Data inserted ......")
#Retrieving data
print("Documents in the collection: ")
for doc in coll.find({"age":{"$gt":"26"}}):
print(doc)
Output
Data inserted ......
Documents in the collection:
{''_id'': ''1002'', ''name'': ''Rahim'', ''age'': ''27'', ''city'': ''Bangalore''}
{''_id'': ''1003'', ''name'': ''Robert'', ''age'': ''28'', ''city'': ''Mumbai''}
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