javaWeb05

删除：先拿到其下标，根据下标删除值

 //设置字符编码
  request.setCharacterEncoding("utf-8");
  //接收nid
  String nid=request.getParameter("nid");
 
   
  
  Class.forName("oracle.jdbc.driver.OracleDriver");
  String url="jdbc:oracle:thin:@localhost:1521:orcl";
  Connection con=DriverManager.getConnection(url, "scott","tiger");
  String sql="delete news279 where nid="+nid;
  PreparedStatement ps=con.prepareStatement(sql);
  int n=ps.executeUpdate();
  if(n>0){
	  //重定向
	  response.sendRedirect("/q4/news/admin.jsp") ;
  }else{
	  out.print("<script>alert('删除失败!');location.href='admin.jsp'; </script>");
  }
//关闭

if(con!=null&&!con.isClosed()){
    	con.close();
    }
    if(ps!=null){
    	ps.close();
    }

修改：根据下标拿值，再把值赋值给增加界面，在增加界面进行修改

 增加：拿到文本框，给文本框赋值

    <% 
    //OracleDriver
    Class.forName("oracle.jdbc.driver.OracleDriver");
    String url="jdbc:oracle:thin:@localhost:1521:orcl";
    Connection con=DriverManager.getConnection(url, "scott","tiger");
    String sql="select * from topic279";
    PreparedStatement ps=con.prepareStatement(sql);
    ResultSet rs=ps.executeQuery();
    while(rs.next()){
    	
    
    
    %>
         
        	    <option value="<%= rs.getInt(1)%>"><%=rs.getString(2)%></option>
         <%
         }
    
    //关闭连接
    if(con!=null&&!con.isClosed()){
    	con.close();
    }
    if(ps!=null){
    	ps.close();
    }
    if(rs!=null){
    	rs.close();
    }
       %>