Untitled

SELECT
  i.invoice_id, i.strata_id, i.internal_description, i.office_code, i.status_code,
  COALESCE(i.date_closed, MAX(d.date_completed), MIN(d.date_started), i.date_opened) date,
  b.name billto_name,
  s.name strata_name,
  c.status status
  FROM invoices i
    LEFT JOIN invoice_billto b
    USING (invoice_id)
    LEFT JOIN stratas s
    USING (strata_id)
    LEFT JOIN invoice_status_codes c
    USING (status_code)
    LEFT JOIN invoice_items d
    USING (invoice_id)