Oracle & MSSQL cross platform SQL

• MSSQL subquery must have a alias name while Oracle does not,
  eg. (Note the last word 'j')

  SELECT MIN(actiontime) min_time FROM(SELECT CASE WHEN o.actiontime > 0 THEN o.actiontime WHEN u.actiontime > 0 THEN u.actiontimeELSE 0 END actiontimeFROM relayed_emails eLEFT JOIN rm_openactions o ON e.id = o.relayed_email_idLEFT JOIN rm_urlactions u ON e.id = u.relayed_email_idWHERE e.delivery = 1 AND (o.actiontime > 0 OR u.actiontime > 0) ) j