SQL error [ORA-00918: column ambiguously defined] in [SELECT * FROM (SELECT a.*,a.userid FROM alerts a WHERE round(a.alertid/100000000000000) in (0) AND ((a.userid+0) IN (1)) AND a.alerttype=0 AND a.clock>1257870600 ORDER BY a.clock DESC) WHERE rownum BETWEEN 0 AND 1001]