题解 | #顾客登录名#
顾客登录名
http://www.nowcoder.com/practice/7cbf5e3082954c21a80fc750ce97350f
concat(s1,s2,s3...)字符连接
upper（s）转大写
substr(s,i,length),i为第i个字符，i>=1
select cust_id,cust_name,
upper(concat(substr(cust_contact,1,2),substr(cust_city,1,3)))
as user_login from Customers;
