Отсутствует параметр IN или OUT с индексом :: 8

    String s1 = "create table testing " +
          "(id number NOT NULL PRIMARY KEY, " +
          "url varchar(1000) NOT NULL, " +
          "urlHash varchar(1000) NOT NULL, " +
          "contentHash varchar(1000), " +
          "modDate date, " +
          "contentLocation varchar(1000), " +
          "status integer, " +
          "lastCrawlDate date) ";
String s2 = "create sequence " +sequenceName+ " start with 1 increment by 1 nomaxvalue";

stmt=conn.createStatement();
stmt.executeUpdate(s1);
stmt.executeUpdate(s2);

What's wrong with this below merge statement I always get error as

Missing IN or OUT parameter at index:: 8

Я пытаюсь преобразовать дату строки String Date DateType в oracle sql в подготовить statment

ps =  conn.prepareStatement(
"MERGE INTO testing " +
"USING (  SELECT ? AS url, " +     //We will maybe add this record
"                ? AS urlHash, " +
"                ? AS contentHash, "+
"        TO_DATE(?, 'YYYY-MM-DD'T'HH24:MI:SS'Z'') AS modDate, "+
"        ? AS contentLocation, "+
"        ? AS status, "+
"      TO_DATE(?, 'YYYY-MM-DD HH24:MI:SS') AS lastCrawlDate "+
"           FROM dual ) maybe "+
"   ON (maybe.urlHash = testing.urlHash) "+
"       WHEN MATCHED THEN "+
// We only need update the fields that might have changed
"       UPDATE SET testing.contentHash     = maybe.contentHash, "+
"                  testing.modDate         = maybe.modDate, "+
"                  testing.contentLocation = maybe.contentLocation, "+
"                  testing.status          = maybe.status, "+
"                  testing.lastCrawlDate   = maybe.lastCrawlDate "+
// But only if the new record is more recent
"        WHERE TO_CHAR(testing.modDate, 'YYYY-MM-DD'T'HH24:MI:SS'Z'') < TO_CHAR(maybe.modDate, ''YYYY-MM-DD'T'HH24:MI:SS'Z''') "+
"       WHEN NOT MATCHED THEN "+
// Insert new URL record
"   INSERT VALUES (test_seq.nextval, maybe.url, maybe.urlHash, maybe.contentHash, maybe.modDate, maybe.contentLocation, maybe.status, maybe.lastCrawlDate)");


    ps.setString (1, "http://www.computergeeks.com");
    ps.setString (2, "ahsasoiowiewie");
    ps.setString (3, "sgasjwhwueybdbfndf");
    ps.setString (4, "2011-07-28T23:54:14Z");
    ps.setString (5, "c://");
    ps.setLong (6, 0);
    ps.setString (7, "2010-09-24 23:34:14"); 
    ps.executeUpdate();
    ps.close();