Oracle数据库中保留小数点后两位的问题解读
作者：無间行者
在Oracle数据库中,对数字和百分比进行格式化,以保留两位小数,主要使用to_char()函数,对于大数字如10000000.12,使用to_char(字段名, 'FM99999999999990.00')可确保保留两位小数而无额外空格,对于百分比如86.63%
Oracle数据库中保留小数点后两位的问题
1.数字保留两位小数
（小数点左侧数字可能比较大，比如10000000.12）
to_char() 函数转换
答案
select trim(to_char(85.7323232, '9999999990.00')) as 两位小数 from dual;
写法对比
select result,
to_char(result, '9999.99') as "位数不足",
to_char(result, '9999999999.99') as "位数充足",
to_char(result, '0000.00') as "0的位数不足",
to_char(result, '0000000000.00') as "0的位数充足",
to_char(result, '9999999990.00') as "9的位数充足",
trim(to_char(result, '9999999990.00')) as "9的位数充足且去掉左侧"
from (
select 0 result from dual union
select 1 result from dual union
select 123 result from dual union
select 123.4 result from dual union
select 12345.67 result from dual union
select 12345678.2 result from dual
)2.百分比保留两位小数
（小数点左侧数字数字小于等于100，比如86.63%）
答案
select trim(to_char(0.7323232 * 100, '99990.99'))||'%' as 百分比 from dual;
select trim(to_char(0.7323232 * 100, '99990.99'))||'%' as 百分比 from dual;
写法对比
select result,
to_char(result * 100, '99.99') || '%' as "9位数不足",
to_char(result * 100, '00.99') || '%' as "0位数不足",
to_char(result * 100, '99990.99') || '%' as "百分比",
trim(to_char(result * 100, '99990.99')) || '%' as "去左侧空格的百分比",
to_char(result * 100, 'fm99990.99') || '%' as "使用fm前缀的格式百分比",
to_char(result * 100, 'fm99990.00') || '%' as "使用fm前缀的格式百分比2"
from (
select 0 result from dual union
select 1 result from dual union
select 0.12345 result from dual union
select 0.2 result from dual union
select 0.23 result from dual union
select 0.234 result from dual union
select 0.2345 result from dual union
select 0.23454 result from dual union
select 0.23456 result from dual
)总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。