Oracle SQL中的"YYYY"和"RRRR"有什么区别 [英] What is the difference between 'YYYY' and 'RRRR' in Oracle SQL

问题描述

我在SQL中有2个查询:

I have 2 queries in SQL:

select trunc(to_date('27-Jul-1987'),'YYYY') FROM dual; 

和

select trunc(to_date('27-Jul-1987'),'RRRR') FROM dual; 

两个都给我相同的结果. "RRRR"和"YYYY"有什么区别?

Both are giving me the same result. What is the difference between 'RRRR' and 'YYYY'?

推荐答案

YYYY给出当前年份为4位数字.

YYYY gives the current year as 4 digits.

RRRR格式表示00到49范围内的两位数字年份被假定为在当前世纪(即，与当前年份相同的前两位数字) ，并且指定为50至99的年份是在上一个世纪.

RRRR format means 2-digit years in the range 00 to 49 are assumed to be in the current century (ie have the same first two digits as the current year), and years given as 50 through 99 are assumed to be in the previous century.

这篇关于Oracle SQL中的"YYYY"和"RRRR"有什么区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！