MongoDB Common Commands - CodeSwordsman

Frequent mongosh commands for connections, CRUD, indexes and execution stats, replica set and sharding status, plus mongodump backups.

MongoDB 5–7 (mongosh)Updated 2026-10-3027 commands

Connections & Databases

Connect with a URI and open the target database directly

mongosh "mongodb://app:<PASSWORD>@10.0.0.12:27017/appdb?authSource=admin"

mongosh --host 10.0.0.12 --port 27017 -u app -p

List databases with their sizes

show dbs

Switch databases; a missing one is created on first write

use appdb

Show collection count, document count and data size

db.stats()

List collections in the current database

show collections

Insert one document; an ObjectId is generated when _id is omitted

db.orders.insertOne({ userId: 42, status: 1, amount: 99.5, createdAt: new Date() })

Bulk insert; ordered writes stop at the first failure by default

db.orders.insertMany([{ userId: 43, status: 1 }, { userId: 44, status: 1 }])

Query with projection, sorting and a limit instead of returning whole documents

db.orders.find({ status: 1 }, { name: 1, amount: 1 }).sort({ _id: -1 }).limit(20)

Update selected fields of one document and keep the rest untouched

db.orders.updateOne({ _id: ObjectId("<ID>") }, { $set: { status: 2 } })

Update every matching document

db.orders.updateMany({ status: 0 }, { $set: { archived: true } })

Risky

Delete matching documents; count them with find first

db.orders.deleteMany({ status: 0 })

Count matching documents; more reliable than count on large collections

db.orders.countDocuments({ status: 1 })

Create a compound index covering the common user-and-time sort

db.orders.createIndex({ userId: 1, createdAt: -1 })

List all indexes on a collection

db.orders.getIndexes()

Inspect documents scanned, timing and index usage

db.orders.find({ userId: 42 }).explain("executionStats")

Risky

Drop an unused index to reduce write overhead

db.orders.dropIndex("userId_1_createdAt_-1")

Aggregate total order amount per user

db.orders.aggregate([{ $match: { status: 1 } }, { $group: { _id: "$userId", total: { $sum: "$amount" } } }])

Show replica set members, roles and replication lag

rs.status()

Initialize a single-node replica set, common in test environments

rs.initiate({ _id: "rs0", members: [{ _id: 0, host: "10.0.0.12:27017" }] })

Show replica set configuration including priority and voting

rs.conf()

Show sharding status, shard keys and chunk distribution

sh.status()

Shard a collection on a hashed key for even write distribution

sh.shardCollection("appdb.orders", { userId: "hashed" })

Dump the database logically into the target directory

mongodump --uri="mongodb://app:<PASSWORD>@10.0.0.12:27017/appdb" --out=/backup/20261030

Restore a dump directory; existing data is kept by default

mongorestore --uri="mongodb://app:<PASSWORD>@10.0.0.12:27017" /backup/20261030

Export a collection to CSV for business review

mongoexport --uri="mongodb://app:<PASSWORD>@10.0.0.12:27017/appdb" --collection=orders --type=csv --fields=id,userId,status --out=/tmp/orders.csv

Exports contain data only, no indexes; use mongodump and mongorestore for restores

Lock writes for a consistent file-level snapshot; always follow with db.fsyncUnlock()

db.fsyncLock()

Writes block while locked, so keep the window short and pair it with a filesystem snapshot