我写的查询有问题。我不知道它在静态上是否正确。有人可以帮我弄这个吗？我还已将数据库模式作为图像附加。enter image description here
编写查询以显示拥有多个帐户的客户的名字。按名字顺序显示记录。
Select firstname from customer_master
where customer_number in (Select count(customer_number) from account_master where count(customer_number)>1
group by customer_number)
order by firstname;