题解 | #顾客登录名#
顾客登录名
https://www.nowcoder.com/practice/7cbf5e3082954c21a80fc750ce97350f
select cust_id, cust_name, # concat 拼接字符串 # ucase/upper 转大写 lcase/lower 转小写 # left(s,n) 返回字符串 s 的前 n 个字符 concat(ucase(left(cust_name,2)),ucase(left(cust_city,3))) as user_login # mid(s,n,length) 从字符串 s 的 n 位置截取长度为 length 的子字符串,用法同 substring # concat(ucase(mid(cust_contact,1,2)),ucase(mid(cust_city,1,3))) as user_login from Customers
