java 在 Oracle 中选择当月的记录
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select records for the Current Month In Oracle
提问by ErrorNotFoundException
Hi Guys I am writing a Java Program where I am required to select Records for the Current Month from an Oracle database. Any time I need to select Records for the Current day I use:
嗨，伙计们，我正在编写一个 Java 程序，我需要从 Oracle 数据库中选择本月的记录。任何时候我需要为我使用的当天选择记录：
select * from purchases where purchase_date = to_char(sysdate, 'DD-MON-YYYY')
What Method should I use to select records from the current Month? On the table the dates appear like:
我应该使用什么方法来选择当月的记录？在表格上，日期显示如下：
10/4/2012 //for 4th October 2012
I tried
我试过
select * from purchases where purchase_date like to_char(sysdate, 'MON-YYYY')
This selects nothing of course please assist.
这当然没有选择，请帮助。
回答by Tulains Córdova
If purchase_dateis a DATE.
如果purchase_date是日期。
select *
from
purchases
where
purchase_date >= trunc(sysdate,'mm')
If purchase_dateis a VARCHAR
如果purchase_date是 VARCHAR
select *
from
purchases
where
to_date(purchase_date,'mm/dd/yyyy') >= trunc(sysdate,'mm')
trunc(sysdate,'mm') truncates the current date keeping the month and obviously the year, so 10/04/2012 08:58is truncated to 10/01/2012 00:00.
trunc(sysdate,'mm') 截断当前日期，保留月份和显然年份，因此10/04/2012 08:58被截断为10/01/2012 00:00.
回答by GriffeyDog
Assuming purchase_date is a VARCHAR2and formatted like DD-MON-YYYY, which appears to be the case, then:
假设 purchase_date 是 aVARCHAR2并且格式为DD-MON-YYYY，这似乎是这种情况，那么：
select * from purchases where trunc(to_date(purchase_date,'DD-MON-YYYY'),'MONTH') = trunc(sysdate,'MONTH')
