小于或等于 Oracle SQL
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LESS THAN OR EQUAL TO IN Oracle SQL
提问by Andromeda
updated_date = 08-Jun-2010;
I have a query like this
我有一个这样的查询
select * from asd whre updated_date <= todate('08-Jun-2010', 'dd-MM-yy');
but I am not getting any results. it only works if todateis 09-Jun-2010...
但我没有得到任何结果。它仅适用todate于 2010 年 6 月 9 日...
i.e. my equaltooperator is not working properly.
即我的equalto操作员工作不正常。
why is it like that?
为什么会这样？
回答by Vincent Malgrat
In Oracle a DATE is a point in time. It always has a time component with a precision to the second. todate('08-Jun-2010', 'dd-Mon-yyyy')is in Oracle the same as todate('08-Jun-2010 00:00:00', 'dd-Mon-yyyy hh24:mi:ss'). So if you select rows up to that date you won't get any row on that day with a time component not equal to 00:00.
在 Oracle 中，日期是一个时间点。它总是有一个精确到秒的时间分量。todate('08-Jun-2010', 'dd-Mon-yyyy')在 Oracle 中与todate('08-Jun-2010 00:00:00', 'dd-Mon-yyyy hh24:mi:ss'). 因此，如果您选择截至该日期的行，则当天不会获得任何时间分量不等于 的行00:00。
If you want to select all the rows up to and including 08-JUN-2010, I would suggest using:
如果您想选择直到并包括 的所有行08-JUN-2010，我建议使用：
< to_date('09-06-2010', 'dd-MM-yyyy')
or
或者
<= to_date('08-06-2010 23:59:59', 'dd-MM-yyyy hh24:mi:ss')
Note- I corrected your date format: you need to use MONif you want to use the abbreviated month name. I would suggest using MMinstead, so that you won't get error when someone changes its client settings (NLS_DATE_LANGUAGE). Also prefer the use of YYYYinstead of YY.
注意- 我更正了您的日期格式：MON如果您想使用缩写的月份名称，则需要使用。我建议MM改为使用，这样当有人更改其客户端设置 ( NLS_DATE_LANGUAGE)时您就不会出错。也更喜欢使用YYYY代替YY。
回答by Sujee
Check this,
检查这个，
select to_date('08-Jun-2010', 'dd-MON-yyyy') from dual;
It is equal to 2010-06-08 00:00:00. Notice the time.
它等于2010-06-08 00:00:00。注意时间。
The updated_datehas time portion. To include them, please use this query,
所述updated_date具有时间部分。要包含它们，请使用此查询，
select * from asd where trunc(updated_date) <= to_date('08-Jun-2010', 'dd-MON-yyyy');
The default TRUNCfunction for date parameter will remove the time.
TRUNCdate 参数的默认函数将删除时间。
Refer Trunc
参考中继
