如何将时间加入数据库？最好给例程

import java.sql.Date ;
import java.sql.Time ;

PreparedStatement ps = conn.prepareStatement("INSERT INTO clientcount(userid,ip,onlinetime,date,time) VALUES(?,?,?,?,?)");

     int i=0;
       ClientCounter clientCounter = (ClientCounter)  vecCounters.elementAt (0);
         ps.setString(1,clientCounter.getUserName ());
         ps.setString (2,clientCounter.getIP ());
         ps.setLong (3,clientCounter.getSecond ());
         ps.setDate (4,new Date(clientCounter.getTime ()));
         ps.setTime(5,new Time(clientCounter.getTime ()));
         ps.execute ();
    

String timeValue="{t '00:00:00'}";
String dateValue="{d '2002-6-1'}";
String dateTimeValue="{ts '2002-6-1 00:00:00'}";
PreparedStatement  ps  =  conn.prepareStatement("INSERT  INTO  table(timeField,dateField,dateTimeField)  VALUES("+timeValue+","+dateValue+","+dateTimeValue+")");

String Str_Date="2002/3/2 0:0:0";
Date d=new Date(Str_Date);