xd_mongo_commands.md

Common Commands

Mongo

• Login as user to a database: mongo --host localhost -u admin -p passsword -authenticationDatabase db
• Show users of one particular database:
  • use my_db;
  • show users;

Database

• There is no CREATE DATABASE statement in MongoDB like there is in SQL. To create a database in MongoDB, simply switch to a non-existent database, then insert data into it: use homstead

User

• Create an user for a specific database:

• Switch to the db use my_db

• Create the user

db.createUser(
   {
     user: "homestead",
     pwd: "secret",
     roles: [ "readWrite", "dbAdmin" ]
   }
);

Collection

• List all collections of a database: show collections;
• Find all: db.collectionName.find({})
• Format result: db.collectionName.find({}).pretty()

Backup a database

• Dump the orginal database: mongodump --db=dev_db --username=dev --password="dev"
• Zip it: zip -r dump.zip dump/
• Download to local
• Restore: mongorestore --username=dev --password="password" --authenticationDatabase=your-db dump/

Troubleshoot

Query Targeting: Scanned Objects / Returned has gone above 1000

Explaination

https://intercom.help/mongodb-atlas/en/articles/892313-understanding-the-query-targeting-alert

Todo

db.students.createIndex({name:1})