postgresql7.1 SELECT s.session_id, s.name, s.title, s.completed_datetime, s.percent_score, p.first_names || ' ' || p.last_name AS subject_name, a.title AS assessment_name, s.subject_id FROM as_sessionsx s, as_assessmentsx a, persons p WHERE s.assessment_id = a.assessment_id AND s.subject_id = p.person_id AND s.assessment_id = :assessment_id AND s.last_mod_datetime IN ( SELECT max(s.last_mod_datetime) as last_mod_datetime FROM as_sessionsx s, as_assessmentsx a, persons p WHERE s.assessment_id = a.assessment_id AND s.subject_id = p.person_id AND s.assessment_id = :assessment_id GROUP BY s.subject_id ) SELECT s.session_id, s.name, s.title, s.completed_datetime, s.percent_score, p.first_names || ' ' || p.last_name AS subject_name, a.title AS assessment_name, s.subject_id FROM as_sessionsx s, as_assessmentsx a, persons p WHERE s.assessment_id = a.assessment_id AND s.subject_id = p.person_id AND s.assessment_id = :assessment_id AND s.subject_id = :subject_id AND s.last_mod_datetime IN ( SELECT max(s.last_mod_datetime) as last_mod_datetime FROM as_sessionsx s, as_assessmentsx a, persons p WHERE s.assessment_id = a.assessment_id AND s.subject_id = p.person_id AND s.assessment_id = :assessment_id AND s.subject_id = :subject_id GROUP BY s.subject_id )