Skill Topic · Cinematic

📘 MongoDB — Aggregation Pipeline

Data ko transform, group, analyze karo — aggregation ka full power! 📊

Topic 1

📌 1. Aggregation Pipeline Kya Hai?

📚 ` Input (Collection) → Stage 1 → Stage 2 → Stage 3 → Output ┌──────────┐ ┌─────────┐…

Topic 2

📌 2. Basic Syntax

💡 `javascript db.collection.aggregate([ { stage1 }, { stage2 }, { stage3 }, // ... ]) //…

Topic 3

📌 3. $match — Filter

🎯 `javascript // ═══ find() jaisa hi — pipeline ke start me use karo ═══…

Topic 4

📌 4. $group — Group & Aggregate

⭐ `javascript // ═══ SQL ke GROUP BY jaisa ═══ db.orders.aggregate([ { $group: { _id:…

Topic 5

📌 5. $project — Reshape

🔑 `javascript // ═══ Fields include/exclude + transform ═══ db.users.aggregate([ {…

Topic 6

📌 6. $sort, $limit, $skip

✨ `javascript // ═══ $sort ═══ db.orders.aggregate([ { $match: { status: "completed" } }, {…

Topic 7

📌 7. $unwind — Array Flatten

🌟 `javascript // ═══ Array ke har element ke liye separate document ═══ // Before: { _id:…

Topic 8

📌 8. $lookup — JOIN

🚀 `javascript // ═══ Left outer join (SQL LEFT JOIN jaisa) ═══ // orders collection: {…

Topic 9

📌 9. $addFields / $set

📚 `javascript // ═══ New fields add karo (existing sabhi rahe) ═══ db.orders.aggregate([ {…

Topic 10

📌 10. $count

💡 `javascript // ═══ Count documents after pipeline ═══ db.orders.aggregate([ { $match: {…

Topic 11

📌 11. $out / $merge — Write Results

🎯 `javascript // ═══ $out — Output to NEW collection (replaces!) ═══ db.orders.aggregate([…

Topic 12

📌 12. Complete Example — Sales Dashboard

⭐ `javascript // ═══ Monthly sales report with top products ═══ db.orders.aggregate([ //…

Topic 13

📌 13. Performance Tips

🔑 ` ┌──────────────────────────────────────────────┐ │ Aggregation Performance Tips │…

Topic 14

✅ Summary

✨ KEY POINTS: - Pipeline = stages ki chain (docs flow through stages) - $match first =…

Quick Quiz

Quiz — Question 1

📘 MongoDB — Aggregation Pipeline ka sabse sahi definition kya hai?

Complete! 🎉

📘 MongoDB — Aggregation Pipeline Complete!

Aliens School · HIEN · Cinematic Knowledge

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