(SELECT DISTINCT z.prname Phase, x.prname, x.prwbslevel, x.prwbssequence, x.wbs_parseq, x.prprojectid
FROM Niku.PRTASK x, 
(SELECT DISTINCT y.prname, y.prwbslevel, y.prwbssequence, y.wbs_parseq, y.prprojectid
FROM Niku.PRTASK y WHERE y.prwbslevel=1 AND y.pristask=0) z
WHERE x.prwbslevel=2 AND x.pristask=0 AND x.wbs_parseq=z.prwbssequence (+) AND x.prprojectid=z.prprojectid (+)) ad,
(SELECT DISTINCT w.prname, w.prwbslevel, w.prwbssequence, w.wbs_parseq, w.prprojectid
FROM Niku.PRTASK w WHERE w.prwbslevel=1 AND w.pristask=0) ph,