摘要：
函数包括:单行函数,多行函数(分组函数)数值函数:--绝对值select abs(-12.3) from dual;--向上取值select ceil(5.3) from dual;--向下取值select floor(5.3 )from dual;--四舍五入select round(123.4124,2)from dual;-- 截取小数点之后select trunc(4252.04524,2) from dual;--次方select power(2,3) from dual;--取余数select mod(12.11,4) from dual;--开方select sqrt(9) fr 阅读全文