Oracle SQL - Last 12 full months of data
<p>I need a query that will dynamically pull the last 12 full months of shipping data (excluding current month). So with today being September 30, 2016, I would need data from September 1, 2015 to August 31, 2016. Tomorrow, the query would change to the date range of 10-1-15 to 9-30-16.</p>

<p>Here is what I have currently:</p>

<pre><code>WHERE (shipdate BETWEEN TRUNC(sysdate, 'Year') AND sysdate)
</code></pre>

<p>This query pulls data from the beginning of the calendar year up to TODAY's date instead of the previous 12 completed months. I have found answers for this with MySQL and MS SQL Server but not for Oracle. How can this be accomplished in Oracle?</p>