Re: removing duplicates and using sort

Yes, that's correct, modifying the original ORDER BY gives:

ORDER BY lastname, firstname, refid, appldate DESC;
ERROR:  SELECT DISTINCT ON expressions must match initial ORDER BY expressions

Using WITH works great:

WITH distinct_query AS (   SELECT DISTINCT ON (refid) id, refid, lastname, firstname, appldate       FROM appl WHERE
lastnameILIKE 'Williamson%' AND firstname ILIKE 'd%'       GROUP BY refid, id, lastname, firstname, appldate
ORDERBY refid, appldate DESC   ) 
SELECT * FROM distinct_query ORDER BY lastname, firstname;

Thank you!