1.power function Definition:The Oracle PL/SQL, the POWER function is a built in function which takes two numeric inputs and returns numeric(数字的) result as first argument raised to second argument. The statement "POWER (a,b)" computes as ( a^b ).…

site:www.mysql.com SUBSTRING_INDEX ----------------------------------------------------------------------------------------------------------- 官方文档: http://dev.mysql.com/doc/refman/5.0/en/string-functions.html  字符串函数 http://dev.mysql.com/doc/refman/5…