ترتيب النتائج باستخدام ORDER BY في SQL

SELECT column1, column2
FROM table_name
ORDER BY column_name [ASC|DESC];

+----+------------------+--------+-------+
| id | name             | price  | stock |
+----+------------------+--------+-------+
| 1  | لابتوب Dell      | 3500   | 15    |
| 2  | ماوس لاسلكي      | 50     | 100   |
| 3  | لوحة مفاتيح      | 120    | 50    |
| 4  | شاشة Samsung     | 800    | 25    |
| 5  | سماعات           | 150    | 60    |
+----+------------------+--------+-------+

SELECT name, price FROM products
ORDER BY price ASC;

+------------------+--------+
| name             | price  |
+------------------+--------+
| ماوس لاسلكي      | 50     | ← الأرخص
| لوحة مفاتيح      | 120    |
| سماعات           | 150    |
| شاشة Samsung     | 800    |
| لابتوب Dell      | 3500   | ← الأغلى
+------------------+--------+
5 rows in set

-- هذان الاستعلامان متطابقان
SELECT name, price FROM products ORDER BY price ASC;
SELECT name, price FROM products ORDER BY price;

SELECT name, price FROM products
ORDER BY price DESC;

+------------------+--------+
| name             | price  |
+------------------+--------+
| لابتوب Dell      | 3500   | ← الأغلى
| شاشة Samsung     | 800    |
| سماعات           | 150    |
| لوحة مفاتيح      | 120    |
| ماوس لاسلكي      | 50     | ← الأرخص
+------------------+--------+
5 rows in set

SELECT name, stock FROM products
ORDER BY stock DESC;

+------------------+-------+
| name             | stock |
+------------------+-------+
| ماوس لاسلكي      | 100   | ← الأكثر
| سماعات           | 60    |
| لوحة مفاتيح      | 50    |
| شاشة Samsung     | 25    |
| لابتوب Dell      | 15    | ← الأقل
+------------------+-------+
5 rows in set

+----+-----------+-----+--------+--------+
| id | name      | age | city   | grade  |
+----+-----------+-----+--------+--------+
| 1  | أحمد      | 20  | الرياض | A      |
| 2  | فاطمة     | 19  | جدة    | B      |
| 3  | محمد      | 20  | الرياض | B      |
| 4  | سارة      | 19  | مكة    | A      |
| 5  | علي       | 20  | جدة    | A      |
| 6  | نورة      | 19  | الدمام | B      |
+----+-----------+-----+--------+--------+

SELECT name, age, grade FROM students
ORDER BY age ASC, name ASC;

+-----------+-----+--------+
| name      | age | grade  |
+-----------+-----+--------+
| سارة      | 19  | A      | ← عمر 19 (مرتب أبجدياً)
| فاطمة     | 19  | B      | ← عمر 19 (مرتب أبجدياً)
| نورة      | 19  | B      | ← عمر 19 (مرتب أبجدياً)
| أحمد      | 20  | A      | ← عمر 20 (مرتب أبجدياً)
| علي       | 20  | A      | ← عمر 20 (مرتب أبجدياً)
| محمد      | 20  | B      | ← عمر 20 (مرتب أبجدياً)
+-----------+-----+--------+
6 rows in set

SELECT name, grade FROM students
ORDER BY grade DESC, name ASC;

+-----------+--------+
| name      | grade  |
+-----------+--------+
| فاطمة     | B      | ← B أولاً (مرتب أبجدياً)
| محمد      | B      | ← B أولاً (مرتب أبجدياً)
| نورة      | B      | ← B أولاً (مرتب أبجدياً)
| أحمد      | A      | ← A ثانياً (مرتب أبجدياً)
| سارة      | A      | ← A ثانياً (مرتب أبجدياً)
| علي       | A      | ← A ثانياً (مرتب أبجدياً)
+-----------+--------+
6 rows in set

SELECT name, price FROM products
WHERE price < 500
ORDER BY price DESC;

+------------------+--------+
| name             | price  |
+------------------+--------+
| سماعات           | 150    | ← الأغلى من المصفاة
| لوحة مفاتيح      | 120    |
| ماوس لاسلكي      | 50     | ← الأرخص من المصفاة
+------------------+--------+
3 rows in set

-- لاحظ: لابتوب (3500) وشاشة (800) لم يظهرا لأنهما >= 500

SELECT name, city, grade FROM students
WHERE city = 'الرياض'
ORDER BY grade DESC;

+-----------+--------+--------+
| name      | city   | grade  |
+-----------+--------+--------+
| محمد      | الرياض | B      |
| أحمد      | الرياض | A      |
+-----------+--------+--------+
2 rows in set

-- هذان الاستعلامان متطابقان
SELECT name, price FROM products ORDER BY price DESC;
SELECT name, price FROM products ORDER BY 2 DESC;
--                                           ↑
--                                  العمود الثاني (price)

-- NULL في البداية
SELECT name, discount FROM products
ORDER BY discount ASC NULLS FIRST;

-- NULL في النهاية
SELECT name, discount FROM products
ORDER BY discount ASC NULLS LAST;

SELECT 
    product_name,
    SUM(quantity) AS total_sold,
    SUM(total_price) AS revenue
FROM sales
GROUP BY product_name
ORDER BY revenue DESC
LIMIT 5;

SELECT name, grade, score FROM students
WHERE score >= 50
ORDER BY grade DESC, score DESC, name ASC;

SELECT name, stock FROM products
WHERE stock < 30
ORDER BY stock ASC;

SELECT order_id, customer_name, order_date, total FROM orders
ORDER BY order_date DESC
LIMIT 10;

SELECT column1, column2
FROM table_name
WHERE condition
ORDER BY column_name
LIMIT number;

-- ✓ الترتيب: SELECT → FROM → WHERE → ORDER BY → LIMIT

-- سيء: غير واضح
SELECT name, price FROM products ORDER BY 2;

-- جيد: واضح
SELECT name, price FROM products ORDER BY price;