for darec in select * from purchbt where addr not like ''%STE%STE%'' and addr not like ''%STE%STE%STE%'' and (addr similar to ''%STE[A-Z]*[0-9]+'' or addr similar to ''%STE[A-Z]*[0-9]+[A-Z]'' or addr similar to ''%STE[A-Z]*[0-9]+[A-Z][A-Z]'') loop
and it finds no records. Outside the function, replace '' with ', I DO get the results I expect. Back and forth, it's reliable.
I tried putting the COUNT(*) into a var and it finds 0 w/in the function and 59K recs as a standalone query.