Using sas or sql add new records to table based on monthly date variables
<p>I need to add records/rows to an existing table, based on values of a couple fields.  The rows are basically the range of months for each different id - most id's will have multiple months but some only one month. </p>

<p>I have a first_date field and a last_date field and need to fill in rows for however intervening months are between the two dates and creating a "time id" for the row identifying that month.     </p>

<p>Current:</p>

<p><a href="https://i.stack.imgur.com/zoCh3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zoCh3.png" alt="enter image description here"></a> </p>