在 oracle 中仅提取当前年份
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Extract only the current year in oracle
提问by A.Wen
I need to get the current year from the oracle db. For an example I need to return 2017 as the answer for the current year as a number type. I tried using following way.
我需要从 oracle 数据库中获取当前年份。例如，我需要将 2017 作为当前年份的答案作为数字类型返回。我尝试使用以下方式。
select to_Number(sysdate, 'YYYY') from student s
But it not works. So what is the easiest way?
但它不起作用。那么最简单的方法是什么？
回答by Gurwinder Singh
You need to_charinstead of to_number
你需要to_char而不是 to_number
select to_char(sysdate, 'YYYY') from student;
That give a string though. you could apply to_numberon it further to convert into number.
不过，这给出了一个字符串。您可以to_number进一步申请以转换为数字。
select to_number(to_char(sysdate, 'YYYY')) from student;
But there is better method using extract:
但是有更好的方法使用extract：
select extract(year from sysdate) from student;
回答by Abdul Razak
get current year start date: trunc (sysdate, 'yyyy')
获取当前年份的开始日期： trunc (sysdate, 'yyyy')
select trunc (sysdate, 'yyyy'),SYSDATE from dual;
get current Month start date:
获取当前月份的开始日期：
select trunc (sysdate, 'mm'),SYSDATE from dual;
select records in a month/year:
选择一个月/一年的记录：
created_date between trunc (sysdate, 'mm') and sysdate;
created_date between trunc (sysdate, 'yyyy') and sysdate;
