title: Insert Where Not Exists not working
body: <p>It's a simple select statement where i'm trying to insert any new updates with a timestamp. For some reason it just doesn't seem to work. Everything looks fine but when I'm testing the query, it doesn't seem to work.</p>
  
  <pre><code>INSERT sandbox.inv_room_type_inventory_snpsht 
  SELECT id, hotel_id, room_type_id, date__, stop_sell, 
     inventory_count, created, modified__, 
     current_timestamp as snapshot_ts FROM user_gp.inv_room_type_inventory
  WHERE    NOT EXISTS
    (SELECT id, hotel_id, room_type_id, date__, stop_sell, 
        inventory_count, created, modified__ 
     FROM sandbox.inv_room_type_inventory_snpsht
    );
  </code></pre>
  
  <p>Could someone please assist</p>