Java数据库连接PreparedStatement的使用详解

public class Demo_2 {  public static void main(String[] args) {    PreparedStatement ps=null;    ResultSet rs=null;    Connection ct=null;    try {      //1.加载驱动      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");      //2.得到连接      ct=DriverManager.getConnection("jdbc:odbc:mytest");      //3.创建PreparedStatement      ps=ct.prepareStatement("select * from Course where Cno=? and Cpno=?");            ps.setString(1,"3");       //给第一个问号赋值      ps.setInt(2,1);      rs=ps.executeQuery();            while(rs.next()){        String Cno=rs.getString(1);        String Cname=rs.getString(2);        int Cpno=rs.getInt(3);        int Ccredit=rs.getInt(4);        System.out.println(Cno+" "+Cname+" "+Cpno+" "+Ccredit);      }              //使用 PreparedStatement添加一条记录//      ps=ct.prepareStatement("insert into Course values(?,?,?,?)");//      ps.setString(1, "8");//      ps.setString(2, "C++");//      ps.setInt(3, 3);//      ps.setInt(4, 2);//      //执行//      int i=ps.executeUpdate();//      if(i==1){//        System.out.print("添加成功");//      }else{//        System.out.print("添加不成功");//      }          } catch (Exception e) {      e.printStackTrace();    }finally{        try {          if(rs!=null){            rs.close();          }          if(ps!=null){             ps.close();          }          if(ct!=null){            ct.close();          }          } catch (Exception e) {          e.printStackTrace();        }    }    }}