Lesson 13: Build a Flexible Product Catalog

// MongoDB Playground Setup
// Copy this to MongoDB Playground or your local MongoDB

// Create our catalog database
use megamart_catalog

// Sample products to get you started
db.products.insertMany([
  {
    name: "Coding Ninja T-Shirt",
    category: "clothing",
    price: 24.99,
    sizes: ["S", "M", "L", "XL"],
    colors: ["black", "navy", "gray"],
    material: "100% cotton",
    inStock: true
  },
  {
    name: "JavaScript Mastery eBook",
    category: "digital",
    price: 39.99,
    format: "PDF",
    pages: 450,
    fileSize: "15MB",
    downloadLink: "https://download.example.com/js-mastery"
  }
])

print("✅ MegaMart catalog initialized!")

-- In SQL, you'd need separate tables or tons of NULL columns
CREATE TABLE products (
  id INT PRIMARY KEY,
  name VARCHAR(255),
  price DECIMAL(10,2),
  -- Clothing fields
  size VARCHAR(10),
  color VARCHAR(50),
  material VARCHAR(100),
  -- Digital fields
  format VARCHAR(20),
  file_size VARCHAR(20),
  download_link VARCHAR(500),
  -- Course fields
  duration_hours INT,
  modules INT,
  instructor VARCHAR(255)
  -- 😱 Most fields are NULL for each product type!
);

// Each product has ONLY the fields it needs
db.products.insertOne({
  name: "MongoDB Masterclass",
  category: "course",
  price: 89.99,
  instructor: "Sarah Chen",
  duration: "8 hours",
  modules: [
    { title: "NoSQL Basics", duration: "45 min" },
    { title: "Document Design", duration: "60 min" },
    { title: "Aggregation Pipeline", duration: "90 min" }
  ],
  skillLevel: "intermediate",
  certificateIncluded: true
})

print("✨ No schema changes needed - just add what makes sense!")

// Add a video game with nested reviews
db.products.insertOne({
  name: "Space Invaders 3000",
  category: "game",
  price: 59.99,
  platforms: ["PC", "PS5", "Xbox"],
  genres: ["Action", "Sci-Fi"],
  rating: "T for Teen",
  systemRequirements: {
    minimum: {
      ram: "8GB",
      storage: "50GB",
      graphics: "GTX 1060"
    },
    recommended: {
      ram: "16GB",
      storage: "100GB",
      graphics: "RTX 3070"
    }
  },
  reviews: [
    { user: "GamerPro", rating: 5, comment: "Best game ever!" },
    { user: "CasualPlayer", rating: 4, comment: "Fun but challenging" }
  ]
})

// Add a bundled product (clothing with accessories)
db.products.insertOne({
  name: "Developer Starter Pack",
  category: "bundle",
  price: 99.99,
  items: [
    {
      type: "clothing",
      name: "Code & Coffee Hoodie",
      sizes: ["M", "L", "XL"]
    },
    {
      type: "accessory",
      name: "Rubber Duck Debugger",
      quantity: 1
    },
    {
      type: "digital",
      name: "IDE Theme Pack",
      formats: ["VSCode", "IntelliJ"]
    }
  ],
  savings: "Save $20 vs buying separately!"
})

print("🎉 Products added with completely different structures!")

// Find all products under $50
db.products.find({ price: { $lt: 50 } })

// Find clothing in specific sizes
db.products.find({
  category: "clothing",
  sizes: { $in: ["L", "XL"] }
})

// Find digital products with instant download
db.products.find({
  category: "digital",
  downloadLink: { $exists: true }
})

// Complex query: Find games for PC with good reviews
db.products.find({
  category: "game",
  platforms: "PC",
  "reviews.rating": { $gte: 4 }
})

// Search within nested documents
db.products.find({
  "items.type": "digital"
})

// Text search across all fields
db.products.createIndex({ "$**": "text" })
db.products.find({ $text: { $search: "JavaScript" } })

// Average price by category
db.products.aggregate([
  {
    $group: {
      _id: "$category",
      avgPrice: { $avg: "$price" },
      count: { $sum: 1 }
    }
  },
  { $sort: { avgPrice: -1 } }
])

// Most popular clothing sizes
db.products.aggregate([
  { $match: { category: "clothing" } },
  { $unwind: "$sizes" },
  {
    $group: {
      _id: "$sizes",
      products: { $sum: 1 }
    }
  },
  { $sort: { products: -1 } }
])

// Bundle savings calculator
db.products.aggregate([
  { $match: { category: "bundle" } },
  { $unwind: "$items" },
  {
    $group: {
      _id: "$name",
      totalItems: { $sum: 1 },
      itemTypes: { $addToSet: "$items.type" }
    }
  }
])

// Review insights
db.products.aggregate([
  { $match: { reviews: { $exists: true } } },
  { $unwind: "$reviews" },
  {
    $group: {
      _id: "$name",
      avgRating: { $avg: "$reviews.rating" },
      reviewCount: { $sum: 1 }
    }
  },
  { $match: { avgRating: { $gte: 4 } } },
  { $sort: { avgRating: -1 } }
])

// Add inventory tracking that works for physical AND digital products
// Hint: Physical products have quantity, digital have licenses
// Your code here:

// Build a query to find "similar products"
// - Same category
// - Similar price range (±20%)
// - At least one matching attribute
// Your code here:

// Create a system for time-limited discounts
// - Add discount info without modifying product structure
// - Query active sales
// - Calculate final prices
// Your code here:

// Insert
db.collection.insertOne({})
db.collection.insertMany([])

// Find
db.collection.find({ field: value })
db.collection.findOne({ field: value })

// Query Operators
{ field: { $gt: value } }    // Greater than
{ field: { $in: [array] } }  // In array
{ field: { $exists: true } } // Field exists
{ $or: [{}, {}] }           // OR condition

// Update
db.collection.updateOne(
  { filter },
  { $set: { field: value } }
)

// Aggregation
db.collection.aggregate([
  { $match: {} },    // Filter
  { $group: {} },    // Group
  { $sort: {} },     // Sort
  { $unwind: "" }    // Expand arrays
])