Question

我有一个看起来像这样的JSP页面：

新的用户名列允许我输入任何字符串，当我点击“更新用户”按钮时，它将更新数据库中的表。

我的数据库结构表中有一个唯一的列AUSERNAME，用于存储用户名，如屏幕截图所示。单击更新按钮后，它将传递新的用户名值并更新表中的该字段。这就是我要实现的目标。

我知道我必须在我的JSP页面中进行如下所示的AJAX调用：

 <script >
    function update(param,param1) {


        var newuser = document.getElementsByName('NewUserName' + param)[0].value;
        var currentuser = document.getElementsByName(param1).value;



        $.ajax({
            type: "POST",
            url: "update.jsp",
            data: { name: newuser,
                current: currentuser

            },
            success:function( msg ) {
                alert( "Data Updated: " + msg );
            },error: function (xhr, ajaxOptions, thrownError) {
                alert(xhr.status);
                alert(thrownError);
            }
        });

    }




</script>

<form method="get" action="migratefolder.jsp">

    <%



        try {



            Class.forName("com.mysql.jdbc.Driver");
            String connectionURL = "jdbc:mysql://localhost:3306/gmc";
            String username = "root";
            String password = "root";
            Connection conn = null;

            conn = DriverManager.getConnection(connectionURL, "root", "root");

            String query = "select ausername, ausertype from auser where AUSTATE='Y'";
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            String str = "<table border=2><tr><th>Username</th><th>New Username</th><th>User Type</th><th>Update</th></tr>";
              int rowid = 0;
  String currentuser=null;
            while (rs.next()) {
                rowid ++;

            currentuser=rs.getString("ausername");
                String autype = rs.getString("ausertype");
                str += "<tr><td><input readonly type=\"value\" name=\""+currentuser+"\" value="+rs.getString("ausername")+" </td><td><input type=\"text\" name=\"NewUserName"+rowid+"\""+
                        "value=\"\"></td> <td>";

                if (autype.equalsIgnoreCase("Superuser")) {
                    str += "<input type=\"radio\" name=\"usertype"+rowid+"\"  value=\"Superuser\" checked> Superuser ";
                }else{
                    str += "<input type=\"radio\" name=\"usertype"+rowid+"\" value=\"Superuser\" > Superuser ";
                }
                if(autype.equalsIgnoreCase("Basic")) {
                    str += " <input type=\"radio\" name=\"usertype"+rowid+"\" value=\"Basic\"  checked > Basic ";
                }else {
                    str += " <input type=\"radio\" name=\"usertype"+rowid+"\" value=\"Basic\"   > Basic ";
                }
                if(autype.equalsIgnoreCase("View")){
                    str += " <input type=\"radio\" name=\"usertype"+rowid+"\" value=\"View\"  checked> View ";
                }else {
                    str += " <input type=\"radio\" name=\"usertype"+rowid+"\" value=\"View\"  > View ";
                }
                str += "</td><td><button type=\"button\" onclick=\"update("+rowid+","+currentuser+")\">Update User</button></td> </tr>";


            }










            out.println(str);
            rs.close();
            stmt.close();
            conn.close();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }

    %>

到目前为止，对于我的update.jsp页面，如下所示：

  <% response.setContentType("text/xml");%>

<%

    String userid=request.getParameter("current");
    String user=request.getParameter("name");
//database connection
    try{
        Class.forName("com.mysql.jdbc.Driver");
    }
    catch (ClassNotFoundException e) {
        e.printStackTrace();
    }

    Connection con=null;
    ResultSet resultSet=null;
    Statement stmt=null;

    int row=0;

    try {
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/gmc", "root", "root");
        String sql = "UPDATE `auser` SET `AUSERNAME`=? WHERE `AUSERNAME`=? ";
        PreparedStatement statement = con.prepareStatement(sql);
        statement.setString(1, user);
        statement.setString(2, userid);
         statement.executeUpdate();

    }
    catch (Exception ex) {
        ex.printStackTrace();


    }

    response.setContentType("text/plain");
    response.setCharacterEncoding("UTF-8");



%>

问题是我可以将新用户名的值传递给数据库，但是我需要指定对当前用户名本身的约束才能更新。如我的代码所示，使用结果集检索用户名值。例如，在第一行中，我需要告诉表将用户名更新为test，其中the constraint itself is USER1.

有什么方法可以在函数更新中获取Username值吗？

Answer 1

更新功能需要微小的更改才能传递值。

您需要像这样通过javascript函数传递值。

<button onclick=update('abc','bcd')></button>

检查以下代码。

<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>

<script>
    function update(param, param1) {

        var newuser = document.getElementsByName('NewUserName' + param)[0].value;
        var currentuser = param1;

        $.ajax({
            type : "POST",
            url : "update.jsp",
            data : {
                name : newuser,
                current : currentuser

            },
            success : function(msg) {
                alert("Data Updated: " + msg);
                location.reload();
            },
            error : function(xhr, ajaxOptions, thrownError) {
                alert(xhr.status);
                alert(thrownError);
            }
        });

    }
</script>

<form method="get" action="migratefolder.jsp">

    <%
        try {

            Class.forName("com.mysql.jdbc.Driver");
            String connectionURL = "jdbc:mysql://localhost:3306/test";
            String username = "root";
            String password = "root";
            Connection conn = null;

            conn = DriverManager.getConnection(connectionURL, "root", "root");

            String query = "select ausername, ausertype from auser where AUSTATE='Y'";
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            String str = "<table border=2><tr><th>Username</th><th>New Username</th><th>User Type</th><th>Update</th></tr>";
            int rowid = 0;
            String currentuser = null;
            while (rs.next()) {
                rowid++;

                currentuser = rs.getString("ausername");
                String autype = rs.getString("ausertype");
                str += "<tr><td><input readonly type=\"value\" name=\"" + currentuser + "\" value="
                        + rs.getString("ausername") + " </td><td><input type=\"text\" name=\"NewUserName" + rowid
                        + "\"" + "value=\"\"></td> <td>";

                if (autype.equalsIgnoreCase("Superuser")) {
                    str += "<input type=\"radio\" name=\"usertype" + rowid
                            + "\"  value=\"Superuser\" checked> Superuser ";
                } else {
                    str += "<input type=\"radio\" name=\"usertype" + rowid + "\" value=\"Superuser\" > Superuser ";
                }
                if (autype.equalsIgnoreCase("Basic")) {
                    str += " <input type=\"radio\" name=\"usertype" + rowid
                            + "\" value=\"Basic\"  checked > Basic ";
                } else {
                    str += " <input type=\"radio\" name=\"usertype" + rowid + "\" value=\"Basic\"   > Basic ";
                }
                if (autype.equalsIgnoreCase("View")) {
                    str += " <input type=\"radio\" name=\"usertype" + rowid + "\" value=\"View\"  checked> View ";
                } else {
                    str += " <input type=\"radio\" name=\"usertype" + rowid + "\" value=\"View\"  > View ";
                }
                str += "</td><td><button type=\"button\" onclick=\"update(" + rowid + ",'"+currentuser+"')\">Update User</button></td> </tr>";

            }

            out.println(str);
            rs.close();
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    %>

ajax-如何获取我的用户名的值？

1 个答案: