oracle to_date 函数与 sysdate
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to_date function with sysdate
提问by ?ll?ll? l? ?ll?ll?
select TO_CHAR(to_date(sysdate, 'DD-MON-YYYY'), 'DAY') FROM DUAL;
When I run this query the output was : SUNDAY. But we know today is Tuesday(1-1-2013). And
当我运行这个查询时，输出是：SUNDAY。但我们知道今天是星期二（1-1-2013）。和
then changed the query as
然后将查询更改为
select TO_CHAR(to_date('01-JAN-2013', 'DD-MON-YYYY'), 'DAY') FROM DUAL;
answer was :TUESDAY.
答案是：星期二。
then Changed query as
然后将查询更改为
select TO_CHAR(to_date(sysdate+1, 'DD-MON-YYYY'), 'DAY') FROM DUAL;
answer is :MONDAY.
答案是：星期一。
When I using the sysdate why it is show SUNDAY as output?
当我使用 sysdate 时，为什么它显示 SUNDAY 作为输出？
I am new in oracle db. Please help me.
我是 oracle db 的新手。请帮我。
回答by Nipun Jain
use this:
用这个：
select TO_CHAR(sysdate, 'DAY') FROM DUAL;
you are using this :
你正在使用这个：
to_date(sysdate, 'DD-MON-YYYY')
which is giving you date=1/1/0013 which is sunday
这给你 date=1/1/0013 这是星期天
回答by Yogendra Singh
Please refer the documentation for sysdate here. Sysdate is already a date data type.
请在此处参考 sysdate 的文档。Sysdate 已经是一种日期数据类型。
Your example query is inappropriate as to_datefunction takes first parameter as String not date.
您的示例查询不合适，因为to_date函数将第一个参数作为 String not date。
Try the simple query below:
试试下面的简单查询：
select TO_CHAR(sysdate, 'DAY') FROM DUAL;
This should return TUESDAYas output.
这应该TUESDAY作为输出返回。
回答by Ishani Gupta
To_dateis used to convert a strin to date. As sysdateis already a date, one must not add add to_date.
To_date用于将字符串转换为日期。由于sysdate已经是日期，因此不得添加 add to_date。
