John,

Not sure I grasped the essence of your message by you could do the following

select master,* ;
from master , events ;
where master.parcel= events.parcel ;
and evType= 1 ;
and Ltr= date()-30 ;
and not exists (select * from events where Parcel= Master Parcel and evType= 2)

assuming that you normalised your event table using evType= 1,2,... for each type of letter.

Not sure about the syntax, one is only sure about SQL syntax when one sees that outcome :):

More in general, you can always "Join" your events table again under another alias, and so compare different dates for different events. And I suspect that by using an OUTER join of some kind, you can get rid of the not exist construction.


HTH,

Marc