Bugungi dars rejasi

Fayllar (CSV/Excel) va RDBMS taqqoslash

RDBMS ning 5 ta asosiy ustuni

Edgar Codd relyatsion modeli (1970)

Primary Key (PK) — Birlamchi kalit

Foreign Key (FK) va Relyatsion yaxlitlik

Relyatsion bog'lanish arxitekturasi

Bilimingizni sinang: PK va FK

ACID tamoyillarining mohiyati

Real hayotiy misol: Bank o'tkazmasi

ERD: Munosabat turlari

SQLite da jadvallar yaratish (Python)

import sqlite3

conn = sqlite3.connect('data/maktab.db')
cursor = conn.cursor()
cursor.execute("PRAGMA foreign_keys = ON;")

# 1. Customers jadvali (Ota jadval)
cursor.execute("""
CREATE TABLE IF NOT EXISTS customers (
    customer_id INTEGER PRIMARY KEY AUTOINCREMENT,
    ism TEXT NOT NULL,
    telefon TEXT UNIQUE NOT NULL
);
""")

# 2. Orders jadvali (Bolalar jadvali - FK orqali bog'langan)
cursor.execute("""
CREATE TABLE IF NOT EXISTS orders (
    order_id INTEGER PRIMARY KEY AUTOINCREMENT,
    customer_id INTEGER NOT NULL,
    summa REAL NOT NULL,
    FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
);
""")
conn.commit()

INNER JOIN so'rovi bilan bog'lash

# Ikkala jadvalni umumiy customer_id bo'yicha birlashtirib o'qish
cursor.execute("""
SELECT 
    orders.order_id,
    customers.ism,
    customers.telefon,
    orders.summa
FROM orders
INNER JOIN customers ON orders.customer_id = customers.customer_id;
""")

for qator in cursor.fetchall():
    print(f"Buyurtma #{qator[0]} | Xaridor: {qator[1]} | Summa: {qator[3]:,} so'm")

Interaktiv savol

Amaliy topshiriq: 3 daraja

Dars xulosasi

• Ma'lumotlar bazasi (RDBMS) — ma'lumotlarni xavfsiz, parallel va qat'iy yaxlitlikda saqlash tizimi.
• Primary Key (PK) satrni unikal aniqlaydi (`UNIQUE` va `NOT NULL`).
• Foreign Key (FK) jadvallarni bog'laydi va relyatsion yaxlitlikni kafolatlaydi.
• ACID tamoyillari tranzaksiyalarning buzilmasligi va ishonchliligini ta'minlaydi.
• SQL JOIN orqali bir nechta bog'langan jadvallardan yagona hisobot olinadi.