-- 1️⃣  Основные операции с БД
CREATE DATABASE db_name;
USE db_name;

-- 2️⃣  Работа с таблицами
CREATE TABLE table_name (col1 datatype, col2 datatype);
DROP TABLE table_name;
ALTER TABLE table_name ADD column_name datatype;

-- 3️⃣  Вставка данных
INSERT INTO table_name (col1, col2) VALUES (val1, val2);

-- 4️⃣  Выборка данных
SELECT * FROM table_name;
SELECT col1, col2 FROM table_name;
SELECT * FROM table_name WHERE condition;

-- 5️⃣  Обновление данных
UPDATE table_name SET col1 = value1 WHERE condition;

-- 6️⃣  Удаление данных
DELETE FROM table_name WHERE condition;

-- 7️⃣  Соединения
SELECT * FROM table1
INNER JOIN table2 ON table1.col = table2.col;
SELECT * FROM table1
LEFT JOIN table2 ON table1.col = table2.col;
SELECT * FROM table1
RIGHT JOIN table2 ON table1.col = table2.col;

-- 8️⃣  Агрегатные функции
SELECT COUNT(*) FROM table_name;
SELECT SUM(col) FROM table_name;
SELECT col, COUNT(*) FROM table_name GROUP BY col;

-- 9️⃣  Сортировка & Ограничения
SELECT * FROM table_name ORDER BY col ASC;   -- or DESC
SELECT * FROM table_name LIMIT n;

-- 🔟  Индексы
CREATE INDEX idx_name ON table_name (col);
DROP INDEX idx_name;

-- 1️⃣1️⃣  Подзапросы
SELECT * FROM table_name
WHERE col IN (SELECT col FROM other_table);

-- 1️⃣2️⃣  Представления
CREATE VIEW view_name AS
SELECT * FROM table_name;
DROP VIEW view_name;