Question

用户点击IDMenu后，它应根据数据库中的菜单表显示价格。

如何使用onclick事件来实现此目标？

<html>
<body>
  <tr>
    <td>ID Menu :</td>
    <%!
Statement stmt;
Connection conn;
ResultSet Rs = null;
String myUrl = "jdbc:mysql://localhost:3306/finalyearproject";
String myQuery;
Boolean bSuccess = false;
%>

      <%
myQuery = "SELECT IDMenu FROM menu ";

Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(myUrl, "root", "admin");

stmt = conn.createStatement();
Rs = stmt.executeQuery(myQuery);
bSuccess = true;
%>


        <td><input list="IDMenu" name="IDMenu" size="20" onchange="myFunction()" required/></td>
        <datalist id="mySelect">
<% while (Rs.next()) {
%>
<option value="<%= Rs.getString(1)%>"></option>
<%
}
conn.close();
%>
</datalist>
  </tr>
  <tr>
    <td>Price :</td>
    <td><input type="text" id="demo" name="Price" value="" size="20" /></td>
    <script>
      function myFunction() {
        var x = document.getElementById("mySelect").value;
        document.geElementById("demo").innerHTML = x;
      }

    </script>
  </tr>
</body>
</html>

Answer 1

在这里你可以在输入中写为“onclick = myfunction（）”

然后将脚本写为：

<script>
  function myFunction() {
    var x = <?= $value_from_db; ?>;
    document.geElementById("demo").innerHTML = x;
  }
</script>

如何使用onclick事件执行此操作？

1 个答案: