MongoDB Database Operations

This chapter introduces the basic operations of the MongoDB database, including database creation, deletion, and querying.

Display all databases

> show dbs
admin    0.000GB
config   0.000GB
local    0.000GB
tizi365  0.000GB

Switch database

Syntax:

use DATABASE_NAME

Example:

> use mydb
switched to db mydb

Display current database name

Enter the db command

> db
test

Create database

You don't need to explicitly create a database. Just switch to a non-existent database using use and insert a piece of data, and the database will be created automatically. Example:

// Switch to a non-existent database
> use mydb
switched to db mydb

// Insert a document into the movie collection (the movie collection will be created automatically if it does not exist)
> db.movie.insert({"name":"tutorials point"})

// Display all databases (mydb database has been created automatically)
> show dbs
local      0.78125GB
mydb       0.23012GB
test       0.23012GB

Note: MongoDB databases and collections do not need to be created in advance; they are automatically created when data is first written.

Delete database

The db.dropDatabase() API can be used to delete the current database. Example:

// Switch to the mydb database
> use mydb
switched to db mydb

// Delete the mydb database
> db.dropDatabase()
> { "dropped" : "mydb", "ok" : 1 }