各种字段对应的set方法
PreparedStatement stat = conn.preparedStatement(sql);
1.VARCHAR2
stat.setString();
2.NUMBER
stat.setString();
3.TIMESTAMP
stat.setTimestamp(int, timestamp);
4.DATE
stat.setDate(int, java.sql.Date);
5.CLOB
Reader reader = new StringReader(value);
stat.setCharacterStream(int,reader,value.length);
