MySQL是否按照写入的顺序执行查询?

MySQL是否按照写入的顺序执行查询?

SELECT SUM(balance) AS Total,  
COUNT(account_id) AS Number,   
CONCAT(c.last_name, ', ', c.first_name) AS Name  
FROM accounts AS a   
INNER JOIN customers AS c  
USING (customer_id)  
GROUP BY (a.customer_id) ORDER BY Name;  

怎么可能 CONCAT(c.last_name, ', ', c.first_name) 客户作为c 直到最后第三行才出现?它不会导致错误。