🔍 MongoDB Advanced Queries

🎯 Darsning Maqsadi

MongoDB'da murakkab so'rovlar, aggregation pipeline va optimizatsiya texnikalarini o'rganish.

📋 Dars Rejasi

Query operators
Aggregation pipeline
Indexing
Performance optimization
Real-world examples

🔍 Query Operators

📊 Comparison Operators

// Taqqoslash operatorlari
db.users.find({ age: { $gte: 18, $lte: 65 } })
db.users.find({ age: { $gt: 25 } })
db.users.find({ age: { $lt: 30 } })
db.users.find({ age: { $ne: 25 } })
db.users.find({ age: { $in: [25, 30, 35] } })
db.users.find({ age: { $nin: [18, 65] } })

// Mavjudlik tekshirish
db.users.find({ email: { $exists: true } })
db.users.find({ phone: { $exists: false } })

// Null qiymatlar
db.users.find({ bio: { $eq: null } })
db.users.find({ bio: { $ne: null } })
            

🔤 String Operators

// Matn operatorlari
db.users.find({ username: { $regex: /^j/, $options: 'i' } })
db.users.find({ email: { $regex: /@gmail\.com$/ } })
db.users.find({ firstName: { $regex: /john/i } })

// Matn uzunligi
db.users.find({ bio: { $exists: true, $ne: "" } })
db.users.find({ bio: { $regex: /.{10,}/ } })
            

🧠 Logical Operators

🔗 AND, OR, NOT

// AND operatori (default)
db.users.find({ 
    age: { $gte: 18 }, 
    isActive: true 
})

// OR operatori
db.users.find({ 
    $or: [
        { age: { $gte: 65 } },
        { age: { $lt: 18 } }
    ]
})

// NOT operatori
db.users.find({ 
    $not: { age: { $gte: 25 } } 
})

// Murakkab mantiq
db.users.find({
    $and: [
        { isActive: true },
        { 
            $or: [
                { age: { $gte: 18 } },
                { role: "admin" }
            ]
        }
    ]
})
            

📊 Array Operators

// Massiv operatorlari
db.users.find({ hobbies: "reading" })
db.users.find({ hobbies: { $all: ["reading", "gaming"] } })
db.users.find({ hobbies: { $size: 3 } })
db.users.find({ hobbies: { $elemMatch: { $regex: /^r/ } } })

// Nested array
db.users.find({ 
    "addresses.city": "New York" 
})
db.users.find({ 
    "addresses": { 
        $elemMatch: { 
            city: "New York", 
            isPrimary: true 
        } 
    } 
})
            

📈 Aggregation Pipeline

🔧 Pipeline Stages

// Oddiy aggregation
db.users.aggregate([
    { $match: { isActive: true } },
    { $group: { 
        _id: "$age", 
        count: { $sum: 1 },
        avgScore: { $avg: "$score" }
    }},
    { $sort: { count: -1 } },
    { $limit: 10 }
])

// Lookup (JOIN o'rniga)
db.posts.aggregate([
    {
        $lookup: {
            from: "users",
            localField: "authorId",
            foreignField: "_id",
            as: "author"
        }
    },
    { $unwind: "$author" },
    { $project: { 
        title: 1, 
        content: 1, 
        "author.username": 1,
        "author.email": 1 
    }}
])
            

📊 Advanced Aggregation

// Murakkab tahlil
db.orders.aggregate([
    // Faqat oxirgi 30 kun
    { $match: { 
        createdAt: { $gte: new Date(Date.now() - 30*24*60*60*1000) } 
    }},
    
    // Guruhlash
    { $group: {
        _id: "$customerId",
        totalOrders: { $sum: 1 },
        totalAmount: { $sum: "$amount" },
        avgAmount: { $avg: "$amount" },
        lastOrder: { $max: "$createdAt" }
    }},
    
    // Filtrlash
    { $match: { totalOrders: { $gte: 5 } } },
    
    // Tartiblash
    { $sort: { totalAmount: -1 } },
    
    // Cheklash
    { $limit: 10 }
])
            

📇 Indexing

🔍 Index Turlari

// Oddiy index
db.users.createIndex({ username: 1 })
db.users.createIndex({ email: 1 })

// Compound index
db.users.createIndex({ 
    isActive: 1, 
    createdAt: -1 
})

// Text index
db.posts.createIndex({ 
    title: "text", 
    content: "text" 
})

// Geospatial index
db.locations.createIndex({ 
    coordinates: "2dsphere" 
})

// Unique index
db.users.createIndex({ 
    email: 1 
}, { unique: true })

// Partial index
db.users.createIndex({ 
    score: 1 
}, { 
    partialFilterExpression: { 
        isActive: true 
    } 
})
            

⚡ Performance Tips

Query patterns - Qanday so'rovlar ko'p ishlatiladi
Compound indexes - Ko'p ustunli indexlar
Covered queries - Index orqali to'liq javob
Index intersection - Bir necha indexni birlashtirish

⚡ Performance Optimization

📊 Query Analysis

// Explain query
db.users.find({ 
    age: { $gte: 25 }, 
    isActive: true 
}).explain("executionStats")

// Profiling
db.setProfilingLevel(2, { slowms: 100 })
db.system.profile.find().sort({ ts: -1 }).limit(5)

// Index usage
db.users.aggregate([
    { $indexStats: {} }
])

// Query optimization
db.users.find({ 
    age: { $gte: 25 }, 
    isActive: true 
}).hint({ age: 1, isActive: 1 })
            

✅ Optimization Tips

Indexes - To'g'ri indexlar
Projection - Kerakli ustunlar
Limit - Natijalarni cheklash
Skip - Skip o'rniga cursor

⚠️ Avoid

Large documents - Katta hujjatlar
N+1 queries - Ko'p so'rovlar
Regex without index - Indexsiz regex
Large sorts - Katta tartiblash

💼 Real-world Examples

📱 E-commerce Analytics

// Eng ko'p sotilgan mahsulotlar
db.orders.aggregate([
    { $unwind: "$items" },
    { $group: {
        _id: "$items.productId",
        totalSold: { $sum: "$items.quantity" },
        totalRevenue: { $sum: { $multiply: ["$items.quantity", "$items.price"] }}
    }},
    { $lookup: {
        from: "products",
        localField: "_id",
        foreignField: "_id",
        as: "product"
    }},
    { $unwind: "$product" },
    { $project: {
        productName: "$product.name",
        totalSold: 1,
        totalRevenue: 1
    }},
    { $sort: { totalSold: -1 } },
    { $limit: 10 }
])
            

📊 User Behavior Analysis

// Foydalanuvchi faollik tahlili
db.user_activities.aggregate([
    { $match: { 
        timestamp: { $gte: new Date("2024-01-01") } 
    }},
    { $group: {
        _id: "$userId",
        totalActivities: { $sum: 1 },
        uniqueDays: { $addToSet: { $dateToString: { 
            format: "%Y-%m-%d", 
            date: "$timestamp" 
        }}},
        lastActivity: { $max: "$timestamp" }
    }},
    { $addFields: {
        activeDays: { $size: "$uniqueDays" }
    }},
    { $match: { 
        totalActivities: { $gte: 10 },
        activeDays: { $gte: 5 }
    }},
    { $sort: { totalActivities: -1 } }
])
            

📝 Xulosa

🎯 O'rganilgan Mavzular

Query operators va mantiqiy operatorlar
Aggregation pipeline va murakkab tahlil
Indexing va performance optimization
Real-world misollar va best practices
Query analysis va monitoring

✅ Keyingi Qadamlar

Replica Sets
Sharding
Change Streams
Atlas Cloud

💡 Maslahatlar

Query patterns'ni tahlil qiling
Indexlarni optimizatsiya qiling
Performance monitoring
Best practices'ga rioya qiling

🏆 Amaliy Mashq

MongoDB bilan to'liq analytics tizimi yarating!