I am working with the datasets of .net I have an Oracle Query which is working fine . but I copy the query as sql statement within Table Adapter wizard and after I clicked the Query Builder button ,there is SQL syntax error. The query is below: SELECT lead_id, NAME, ADDRESS, CITY, EMAIL, PHONE, PINCODE, STATE, QUALIFICATION, DOB, status FROM (SELECT l.lead_id, l.NAME, l.ADDRESS, l.CITY, l.EMAIL, l.PHONE, l.PINCODE, l.STATE, l.QUALIFICATION, l.DOB, CASE WHEN s.status IS NULL THEN 'Not Updated !' ELSE s.status END status, row_number() over(PARTITION BY l.lead_id ORDER BY t .CREATED_DATE DESC) rn FROM LEADS l JOIN Leads lc ON l.USER_ID = lc.USER_ID AND l.USER_ID = :iuser_id AND(l.CREATED_DATE BETWEEN (TO_DATE(:ifrom_date , 'dd-mm-yyyy') ) AND (TO_DATE (:ito_date, 'dd-mm-yyyy' ) )) LEFT JOIN LEADTRANSACTION t ON l.lead_id = t .lead_id LEFT JOIN STATUS s ON s.STATUS_ID = t .STATUS_ID) WHERE rn = 1;