转换大小写、计算字符串长度和翻转字符串

用length函数计算字符串长度， 用lower函数把字符串转换成小写， 用upper函数把字符串转换成大写， 用reverse函数翻转字符串，用表格展示

source :bill |
select
  length(SubscriptionType) as "字符串长度",
  SubscriptionType as "原字符串",
  lower(SubscriptionType) as "转换成小写",
  upper(SubscriptionType) as "转换成大写",
  reverse(SubscriptionType) as "翻转字符串"

SQL查询结果样例：