CREATE TABLE `transactions` (
    id INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
    channel_id INT(11) UNSIGNED NOT NULL,
    code VARCHAR(255) NOT NULL,
    type VARCHAR(255) NOT NULL,

    total INT(11) NOT NULL,

    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, 

    PRIMARY KEY (`id`),
    FOREIGN KEY (`channel_id`) REFERENCES channels(`id`)
);