在codeigniter中调用存储过程

CREATE PROCEDURE getUserById(IN userId INT)
BEGIN
    SELECT * FROM users WHERE id = userId;
END;

public function getUserById($userId)
{
    // 调用存储过程
    $query = $this->db->query("CALL getUserById({$userId})");

    // 获取结果
    $result = $query->result();

    // 关闭连接
    $query->next_result();
    $query->free_result();

    return $result;
}