Oracle在一个月内获得所有日期(Oracle get all dates in a month)

Oracle在一个月内获得所有日期(Oracle get all dates in a month)

我正在尝试编写一个SQL语句，它可以让我检索9月份创建的所有订单，而不会带来太多好运。

不工作：

select order_number, created_date from orders where created_date in to_date('2012-09', 'YYYY-MM');

工作但太长时间：

select order_number, created_date from orders where trunc(created_date) between to_date('2012-09-01', 'YYYY-MM-DD') and to_date('2012-09-30', 'YYYY-MM-DD');

I am trying to write an SQL statement that would allow me to retrieve all the orders created in the month of September without much luck.

Not working:

select order_number, created_date from orders where created_date in to_date('2012-09', 'YYYY-MM');

Working but too long:

select order_number, created_date from orders where trunc(created_date) between to_date('2012-09-01', 'YYYY-MM-DD') and to_date('2012-09-30', 'YYYY-MM-DD');

最满意答案

怎么样：

select order_number, created_date from orders where created_date >= to_date('2012-09-01', 'YYYY-MM-DD') and created_date < to_date('2012-10-01', 'YYYY-MM-DD');

你应该试着保持created_date不变，以确保你可以很好地利用它的索引。

How about:

select order_number, created_date from orders where created_date >= to_date('2012-09-01', 'YYYY-MM-DD') and created_date < to_date('2012-10-01', 'YYYY-MM-DD');

You should try to leave created_date untouched to make sure that you can leverage indexes on it nicely.