title: Appending data in SAS and overwriting when it already exists
body: <p>I'm writing a macro job that appends a dataset to an existing one (the macro paramater is a date).</p>
  
  <p>If that date exists, I want to overwrite the data for all of those dates.</p>
  
  <p>What is the best way to tackle this?</p>
  
  <p>If it was in SQL i would delete the rows the insert them.  Some SQL languages let you do a replace into if you state a Key.  Should I apply a similar theory to SAS?</p>