CREATE TABLE categories (
    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    business_id INT UNSIGNED NOT NULL,
    name VARCHAR(80) NOT NULL,
    icon VARCHAR(10) DEFAULT NULL,
    is_default TINYINT(1) NOT NULL DEFAULT 0,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    CONSTRAINT fk_categories_business FOREIGN KEY (business_id) REFERENCES businesses(id) ON DELETE CASCADE,
    UNIQUE KEY uniq_category_per_business (business_id, name),
    INDEX idx_categories_business (business_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;