MongoDB Operations Cheatsheet
Quick reference for MongoDB: CRUD operations, queries, aggregation pipelines, indexes, and collection management.
| Operation | Description | Example | Category |
|---|---|---|---|
| insertOne() | Insert a single document | db.users.insertOne({name: "Alice", age: 25}) | CRUD |
| insertMany() | Insert multiple documents | db.users.insertMany([{name:"Bob"}, {name:"Charlie"}]) | CRUD |
| find() | Find documents | db.users.find({age: {$gt: 20}}) | Queries |
| findOne() | Find single document | db.users.findOne({name: "Alice"}) | Queries |
| updateOne() | Update one document | db.users.updateOne({name:"Alice"}, {$set:{age:26}}) | CRUD |
| updateMany() | Update multiple documents | db.users.updateMany({age: {$lt:18}}, {$set:{minor:true}}) | CRUD |
| replaceOne() | Replace document entirely | db.users.replaceOne({name:"Alice"}, {name:"Alice", age:30}) | CRUD |
| deleteOne() | Delete one document | db.users.deleteOne({name:"Bob"}) | CRUD |
| deleteMany() | Delete multiple documents | db.users.deleteMany({age:{$lt:18}}) | CRUD |
| $eq, $ne, $gt, $gte, $lt, $lte | Comparison operators | db.users.find({age: {$gte:18}}) | Queries |
| $in, $nin | Match any / none in array | db.users.find({name: {$in:["Alice","Bob"]}}) | Queries |
| $and, $or, $not, $nor | Logical operators | db.users.find({$or:[{age:18},{age:21}]}) | Queries |
| sort() | Sort documents | db.users.find().sort({age:-1}) | Queries |
| limit() | Limit number of documents | db.users.find().limit(5) | Queries |
| skip() | Skip documents | db.users.find().skip(5) | Queries |
| createIndex() | Create index | db.users.createIndex({name:1}) | Indexes |
| dropIndex() | Remove index | db.users.dropIndex({name:1}) | Indexes |
| aggregate() | Aggregation pipeline | db.orders.aggregate([{$match:{status:"shipped"}}, {$group:{_id:"$customerId", total:{$sum:"$amount"}}}]) | Aggregation |
| $match, $group, $project, $sort, $limit, $lookup | Pipeline stages | db.collection.aggregate([{$match:{field: "value"}}]) | Aggregation |
| distinct() | Unique values | db.users.distinct("name") | Others |
| countDocuments() | Count documents | db.users.countDocuments({age:{$gte:18}}) | Others |
| drop() | Drop collection | db.users.drop() | Others |
| renameCollection() | Rename collection | db.users.renameCollection("new_users") | Others |