Use nvl function in livereport

Rodrigue_Raoul_Minga_(rodrigue.raoulminga@socomec.

I try to do a livereport using nvlHere my sql request :SELECT name, c.MIMETYPE, COUNT(*) "Acces" FROM DAUDITNEW a, DTree, DVersdata c, (select dataid from DTree start with PARENTID=%1 connect by prior DATAID=PARENTID)x WHERE a.DataId = DTree.DataId and x.dataid=a.dataid AND a.AUDITSTR ='Fetch' and PERFORMERID=nvl(%2, PERFORMERID) AND DTree.DataId= c.DocId AND DTree.VersionNum = c.Version GROUP BY name, c.MIMETYPE, DTree.parentid ORDER BY 3 DESCThe problem is is %2 is null value, my result is foud by my request. Thank you for your help