Projection In MongoDB | Performance Optimization

Projection In MongoDB | MongoDB Query Optimization & Performance Explained in Hindi Learn MongoDB Projection and how to retrieve only the required fields from MongoDB documents using "find()" queries. In this MongoDB tutorial in Hindi, you'll understand field inclusion and exclusion, the special behavior of "_id", common projection mistakes, and how MongoDB Projection helps reduce unnecessary data transfer and improve application performance. 📚 Resources & Notes: 🔗 Source Code: https://github.com/CodeKiDaru/Backend... 📄 Lecture Notes (PDF): https://drive.google.com/drive/folder... 💡 Key Takeaway: MongoDB Projection allows you to control which fields are returned from a document instead of retrieving unnecessary data. The second parameter of "find()" accepts a projection object where "1" includes a field and "0" excludes it. For example, "db.users.find({}, { name: 1, username: 1, _id: 0 })" returns only the "name" and "username" fields. Remember that MongoDB includes "_id" by default unless explicitly excluded. Also, inclusion and exclusion should not be mixed in the same projection, except when excluding "_id". By returning only the fields your application needs, MongoDB Projection can reduce network transfer, response payload size, and unnecessary data processing. This makes Projection an important technique for building efficient MongoDB queries and backend APIs. 💬 Comment Challenge: Suppose your "users" collection contains these fields: "name", "username", "email", "phone", "website", "address", "company", "_id" Write MongoDB Projection queries to: 1. Return only "name" and "email" without "_id". 2. Return every field except "phone" and "website". 3. Return only "username" and "company". 4. Exclude "address" and "company" while keeping all other fields. Bonus: What happens if you use "{ name: 1, email: 0 }" in the same projection? Share your MongoDB queries in the comments! ⏱️ CHAPTERS: 00:00 Introduction: What Is Projection in MongoDB? 00:44 Setting Up MongoDB in VS Code and Compass 02:02 Creating a Database and Users Collection 03:25 Inserting Sample User Data Using JSONPlaceholder 04:22 Understanding Why MongoDB Projection Is Needed 05:15 Query Filters vs Projection in "find()" 06:09 Including Specific Fields Using "1" 07:04 Applying Projection Without Query Filters 08:17 Why MongoDB Returns "_id" by Default 08:46 How to Exclude "_id" Using "_id: 0" 09:37 Excluding Fields Using "0" in MongoDB Projection 10:17 Common Mistake: Mixing Inclusion and Exclusion 11:21 Excluding Nested Documents from Query Results 12:28 Special Case: Combining Field Inclusion with "_id: 0" 13:44 MongoDB Projection Performance Benefits 14:42 MongoDB Projection Summary and Best Practices . . . 🍷 Everything is 100% FREE — Make sure to follow on all platforms and tap every link to get full access to content and community support! 🌐 Visit the Website NOW 🔗 https://codekidaru.com 🔖 Don’t miss out — 📌Bookmark it! 👨🏻‍💻 Access All Source Code — Only on GitHub! Follow and explore 🔗 https://github.com/codekidaru 🅾 𝐈𝐧𝐬𝐭𝐚𝐠𝐫𝐚𝐦 (OFFICIAL) 🔗   / codekidaru   📥 DMs are open — Let’s grow together! 🅾 𝐈𝐧𝐬𝐭𝐚𝐠𝐫𝐚𝐦 (PERSONAL) 🔗   / manaskumarlal   📥 DMs are open — Let’s grow together! 𝕏 Twitter 🔗 https://x.com/codekidaru ℹ️LinkedIn 🔗   / manaskumarlal   ▶️YouTube : Want motivation, life guidance, social values, and help in reaching your goals? 🔗    / @manaskumarlal   #MongoDB #MongoDBTutorial #MongoDBInHindi #MongoDBProjection #MongoDBPerformance #MongoDBOptimization #MongoDBQueries #MongoDBFind #DatabaseOptimization #NoSQL #BackendDevelopment #MERNStack #CodeKiDaru #Code #Ki #Daru #Programming #Coding #manaskumarlal #SoftwareEngineering #CodingTutorials #ProgrammingTutorials