Python MongoDBFind
In MongoDB we use thefind() andfind_one() methods to find data in a collection.
Just like theSELECT 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 thefind_one() method.
Thefind_one() method returns the first occurrence in the selection.
Example
Find the first document in the customers collection:
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
x = mycol.find_one()
print(x)
Find All
To select data from a table in MongoDB, we can also use thefind() method.
Thefind() method returns all occurrences in the selection.
The first parameter of thefind() method is a query object. In this example we use an empty query object, which selects all documents in the collection.
No parameters in the find() method gives you the same result asSELECT * in MySQL.
Example
Return all documents in the "customers" collection, and print each document:
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
for x in mycol.find():
print(x)
Return Only Some Fields
The second parameter of thefind() method is an object describing which fields to include in the result.
This parameter is optional, and if omitted, all fields will be included in the result.
Example
Return only the names and addresses, not the _ids:
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
for x in mycol.find({},{ "_id": 0, "name": 1, "address": 1 }):
print(x)
You are not allowed to specify both 0 and 1 values in the same object (except if one of the fields is the _id field). If you specify a field with the value 0, all other fields get the value 1, and vice versa:
Example
This example will exclude "address" from the result:
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
for x in mycol.find({},{ "address": 0 }):
print(x)
Example
You get an error if you specify both 0 and 1 values in the same object (except if one of the fields is the _id field):
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]
for x in mycol.find({},{ "name": 1, "address": 0 }):
print(x)
