Movatterモバイル変換


[0]ホーム

URL:


Menu
×
Sign In
+1 Get Certified For Teachers Spaces Plus Get Certified For Teachers Spaces Plus
   ❮     
     ❯   

Python Tutorial

Python HOMEPython IntroPython Get StartedPython SyntaxPython CommentsPython VariablesPython Data TypesPython NumbersPython CastingPython StringsPython BooleansPython OperatorsPython ListsPython TuplesPython SetsPython DictionariesPython If...ElsePython MatchPython While LoopsPython For LoopsPython FunctionsPython LambdaPython ArraysPython Classes/ObjectsPython InheritancePython IteratorsPython PolymorphismPython ScopePython ModulesPython DatesPython MathPython JSONPython RegExPython PIPPython Try...ExceptPython String FormattingPython User InputPython VirtualEnv

File Handling

Python File HandlingPython Read FilesPython Write/Create FilesPython Delete Files

Python Modules

NumPy TutorialPandas TutorialSciPy TutorialDjango Tutorial

Python Matplotlib

Matplotlib IntroMatplotlib Get StartedMatplotlib PyplotMatplotlib PlottingMatplotlib MarkersMatplotlib LineMatplotlib LabelsMatplotlib GridMatplotlib SubplotMatplotlib ScatterMatplotlib BarsMatplotlib HistogramsMatplotlib Pie Charts

Machine Learning

Getting StartedMean Median ModeStandard DeviationPercentileData DistributionNormal Data DistributionScatter PlotLinear RegressionPolynomial RegressionMultiple RegressionScaleTrain/TestDecision TreeConfusion MatrixHierarchical ClusteringLogistic RegressionGrid SearchCategorical DataK-meansBootstrap AggregationCross ValidationAUC - ROC CurveK-nearest neighbors

Python DSA

Python DSALists and ArraysStacksQueuesLinked ListsHash TablesTreesBinary TreesBinary Search TreesAVL TreesGraphsLinear SearchBinary SearchBubble SortSelection SortInsertion SortQuick SortCounting SortRadix SortMerge Sort

Python MySQL

MySQL Get StartedMySQL Create DatabaseMySQL Create TableMySQL InsertMySQL SelectMySQL WhereMySQL Order ByMySQL DeleteMySQL Drop TableMySQL UpdateMySQL LimitMySQL Join

Python MongoDB

MongoDB Get StartedMongoDB Create DBMongoDB CollectionMongoDB InsertMongoDB FindMongoDB QueryMongoDB SortMongoDB DeleteMongoDB Drop CollectionMongoDB UpdateMongoDB Limit

Python Reference

Python OverviewPython Built-in FunctionsPython String MethodsPython List MethodsPython Dictionary MethodsPython Tuple MethodsPython Set MethodsPython File MethodsPython KeywordsPython ExceptionsPython Glossary

Module Reference

Random ModuleRequests ModuleStatistics ModuleMath ModulecMath Module

Python How To

Remove List DuplicatesReverse a StringAdd Two Numbers

Python Examples

Python ExamplesPython CompilerPython ExercisesPython QuizPython ServerPython SyllabusPython Study PlanPython Interview Q&APython BootcampPython CertificatePython Training

Python MongoDBCreate Database


Creating a Database

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.

Example

Create a database called "mydatabase":

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")

mydb = myclient["mydatabase"]
Run example »

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).


Check if Database Exists

Remember: In MongoDB, a database is not created until it gets content, so if this is your first time creating a database, you should complete the next two chapters (create collection and create document) before you check if the database exists!

You can check if a database exist by listing all databases in you system:

Example

Return a list of your system's databases:

print(myclient.list_database_names())
Run example »

Or you can check a specific database by name:

Example

Check if "mydatabase" exists:

dblist = myclient.list_database_names()
if "mydatabase" in dblist:
  print("The database exists.")
Run example »

 
Track your progress - it's free!
 

×

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail:
help@w3schools.com

W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning.
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness
of all content. While using W3Schools, you agree to have read and accepted ourterms of use,cookie and privacy policy.

Copyright 1999-2025 by Refsnes Data. All Rights Reserved.W3Schools is Powered by W3.CSS.


[8]ページ先頭

©2009-2025 Movatter.jp