MySQL字符串大小写转换函数

符串复制mysql> select lower(DDD);   +--------------+   | lower(DDD) |   +--------------+   | ddd          |   +--------------+   mysql> select upper(ddd);   +--------------+   |upper(ddd) |   +--------------+   | DDD          |   +--------------+   mysql> select lcase(DDD);   +--------------+   | lcase(DDD) |   +--------------+   | ddd          |   +--------------+   mysql> select ucase(ddd);   +--------------+   | ucase(ddd) |   +--------------+   | DDD          |   +--------------+  1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.