SQL Oracle，使日期时间为其月份的第一天
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Oracle, Make date time's first day of its month
提问by Bilgin K?l??
I have a datevariable, I would like to have convert it to first day of its monh,
我有一个日期变量，我想将其转换为月份的第一天，
- Eg: 10/10/2010 -> 01/10/2010
- Eg: 31/07/2010 -> 01/07/2010
- 例如：10/10/2010 -> 01/10/2010
- 例如：31/07/2010 -> 01/07/2010
回答by MatBailie
According to http://psoug.org/reference/date_func.html, this should work a dandy...
根据http://psoug.org/reference/date_func.html，这应该工作一个花花公子......
SELECT TRUNC(yourDateField, 'MONTH') FROM yourTable
回答by BQ.
SQL> select to_date('31/07/2010', 'DD/MM/YYYY') from dual;
TO_DATE('
---------
31-JUL-10
SQL> select trunc(to_date('31/07/2010', 'DD/MM/YYYY'), 'MM') from dual;
TRUNC(TO_
---------
01-JUL-10
SQL>
回答by schurik
select trunc(sysdate, 'mm') from dual;
回答by Ashish4434
try this one
试试这个
select trunc(sysdate, 'MM')firstday , trunc(last_DAY(sysdate)) lastday from dual;回答by Erwin Brandstetter
SELECT trunc(to_date('22-AUG-03'), 'MON') FROM dual;
More in the manual.
About Oracle needing a dummy FROM: Select without a FROM clause in Oracle
手册中有更多内容。
关于 Oracle 需要一个虚拟对象FROM：在 Oracle 中不使用 FROM 子句进行选择
回答by westman379
Here is a good example:
这是一个很好的例子：
select trunc(to_date('15.11.2019', 'DD.MM.YYYY'), 'MONTH') from dual;
