Check Version
mongod --version
mongo -version
Connection
# Local
mongo --port 28015
# Remote
mongo --host mongodb0.example.com:28015
Authentication
# If you specify --password without the user’s password, the shell will prompt for the password.
mongo --username alice --password --authenticationDatabase admin --host mongodb0.examples.com --port 28015
Working with the mongo Shell
# To display the database you are using, type db:
db
# use anther db after connect
use <database>
db.stats()
output
{ "db" : "MyDB", "collections" : 16, "views" : 0, "objects" : 562434, "avgObjSize" : 904.5233894110243, "dataSize" : 508734708, "storageSize" : 146960384, "numExtents" : 0, "indexes" : 17, "indexSize" : 8900608, "fsUsedSize" : 76155506688, "fsTotalSize" : 107004026880, "ok" : 1 }
Authentication Database
When adding a user, you create the user in a specific database.
This database is the authentication database for the user.
The user’s name and authentication database serve as a unique identifier for that user.
[1] That is, if two users have the same name but are created in different databases, they are two separate users.
If you intend to have a single user with permissions on multiple databases,
create a single user with roles in the applicable databases instead of creating the user multiple times in different databases.