如何在java中自动增加mysql中的用户id [英] How to auto increment user id in mysql in java

问题描述

无法在上面的代码中自动增加ID

cannot auto increment id in above code

{
           String sql = "insert into artist_reg_ml (id,uname,pwd,email,country) values (?,?,?,?,?)";
           PreparedStatement pst = conn.prepareStatement(sql);
           pst.setString(1, "5");
           pst.setString(2, uname);
           pst.setString(3, pwd);
           pst.setString(4, email);
           pst.setString(5, country);

           int i = pst.executeUpdate();
           String msg = "";
           if (i != 0) {
               //msg = "Record has been inserted";
               //pw.print("<font size='6' color=blue>" + msg + "</font>");
               HttpSession sess = request.getSession();
               sess.setAttribute("uname", request.getParameter("uname"));
               sess.setAttribute("pwd", request.getParameter("cpwd"));
               RequestDispatcher dispatcher = request.getRequestDispatcher("/mypage1.jsp");
               dispatcher.forward(request, response);
               File dir = new File("C:/Users/Naresh/Documents/NetBeansProjects/Registrationform/web/nameoffolder/" + uname);
               dir.mkdir();

           }

推荐答案

参见 https://dev.mysql.com/doc/refman/5.0/en/example-auto-increment.html [ ^ ]。

试试这个..它的工作原理

try this.. it works

{
            PreparedStatement pst1 = conn.prepareStatement("select max(id)+1 from artist_reg_ml");
            ResultSet rs = pst1.executeQuery();
            String user_id ="" ;
            while(rs.next())
            {
                user_id = rs.getString(1);
            }
            String sql = "insert into artist_reg_ml (id,uname,pwd,email,country) values (?,?,?,?,?)";
            PreparedStatement pst = conn.prepareStatement(sql);
            pst.setString(1, user_id.toString());
            pst.setString(2, uname);
            pst.setString(3, pwd);
            pst.setString(4, email);
            pst.setString(5, country);
            int i = pst.executeUpdate();
            
            String msg = "";
            if (i != 0) {
           
                HttpSession sess = request.getSession();
                sess.setAttribute("uname", request.getParameter("uname"));
                sess.setAttribute("pwd", request.getParameter("cpwd"));
                File dir = new File("C:/Users/Naresh/Documents/NetBeansProjects/Registrationform/web/nameoffolder/" + uname);
                dir.mkdir();
                RequestDispatcher dispatcher = request.getRequestDispatcher("/mypage1.jsp");
                dispatcher.forward(request, response);
             

            } 

这篇关于如何在java中自动增加mysql中的用户id的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！