-- Chỉ chạy trên CSDL THỬ NGHIỆM sau khi sao lưu.
ALTER TABLE nl_available_trips ADD COLUMN owner_phone VARCHAR(25) NULL DEFAULT NULL;
CREATE TABLE IF NOT EXISTS nl_trip_assignments (
 id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
 request_code VARCHAR(80) NOT NULL UNIQUE,
 trip_id BIGINT UNSIGNED NOT NULL,
 status VARCHAR(30) NOT NULL DEFAULT 'pending',
 token_hash CHAR(64) NULL UNIQUE,
 token_plain CHAR(48) NULL,
 created_at DATETIME NOT NULL,
 responded_at DATETIME NULL,
 INDEX(trip_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;