This example illustrates use of LEFT JOIN action.
This query retrieves all event names and places where they happen. Venue is attached to event name if value of field "VenueNo" is equal in both tables. If there is no corresponding venue for event, then NULL is placed beside it.
select e1."Event_Name", v2."Venue"
from "events" e1
leftouterjoin "venues" v2
on (e1."VenueNo" = v2."VenueNo")
orderby e1."Event_Name" asc, v2."Venue" asc