MongoDB CRUD Operations Guide

Connect to MongoDB

MongoDB connection create karna aur data operations start karna simple aur scalable hota hai.

import mongoose from "mongoose"
mongoose.connect("mongodb://localhost:27017/myapp")

const db = mongoose.connection
db.once("open", () => console.log("Connected to MongoDB"))

Create Schema and Model

Schema aur model define karna structured data aur validation ke liye essential hai.

const userSchema = new mongoose.Schema({
  name: String,
  age: Number
})

const User = mongoose.model("User", userSchema)

Insert Documents

Data insert karna easy hai, multiple documents ek sath ya single add kiya ja sakta hai.

await User.create({ name: "Ali", age: 25 })

Query Data

MongoDB se data retrieve karna simple aur flexible queries ke saath possible hai.

const users = await User.find({ age: { $gt: 20 } })
console.log(users)

Update Documents

Existing documents update karna MongoDB me straightforward hai, dynamic aur conditional updates support ke saath.

await User.updateOne({ name: "Ali" }, { $set: { age: 26 } })

Delete Documents

Documents remove karna MongoDB me easy hai, filter aur conditions ke saath.

await User.deleteOne({ name: "Ali" })

Aggregation for Analytics

Aggregation pipelines data analyze aur summarize karne ke liye use hote hain.

const stats = await User.aggregate([{ $group: { _id: "$age", total: { $sum: 1 } } }])
console.log(stats)

Indexing for Performance

Indexes queries fast banate hain, large datasets me performance improve hoti hai.

userSchema.index({ name: 1 })

Validation and Constraints

Validation rules aur constraints data consistency aur integrity maintain karte hain.

const userSchema = new mongoose.Schema({
  name: { type: String, required: true },
  age: { type: Number, min: 0 }
})

Transactions for Atomic Operations

Transactions multiple operations ko atomic banate hain, data consistency ensure karte hain.

const session = await mongoose.startSession()
session.startTransaction()

await User.create([{ name: "Zubair" }], { session })
await session.commitTransaction()
session.endSession()