Html 如何在 Javascript 中编写数据库连接？
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How to write a database connection in Javascript?
提问by Vasu
I want to connect to a database depending on the data enter in a .jspform. I do not know how to connect to database in a Javascript.
我想根据.jsp表单中输入的数据连接到数据库。我不知道如何在Javascript.
My code as follows:
我的代码如下：
<%@ page contentType="text/html; charset=iso-8859-1" language="java" %>
<html>
<head>
<script>
function validateForm()
{
if(document.frm.username.value=="srinu")
{
// conect database here
}
else
{
alert("wrong input");
document.frm.pwd.focus();
return false;
}
}
Body here, i want to connect database based on the details entered in the body.
正文在这里，我想根据正文中输入的详细信息连接数据库。
<body>
<form name="frm" method="get" action="validateInput.jsp" onSubmit="return validateForm()">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="22%"> </td>
<td width="78%"> </td>
</tr>
<tr>
<td>UserName </td>
<td><input type="text" name="username" /></td>
</tr>
<tr>
<td> </td>
<td><input type="submit" name="submit" value="Submit"></td>
</tr>
<tr>
<td> </td>
<td> </td>
</tr>
</table>
</form>
</body>
</html>
回答by Nuwan Dammika
You can not connect to database from client side. JavaScript run on a browser which has a very strict security restrictions. And keeping any connection string on JavaScript is not a good practice at all . Don't keep any sensitive things on client side. Make a call to server side validate and work on that.
您无法从客户端连接到数据库。JavaScript 在具有非常严格的安全限制的浏览器上运行。并且在 JavaScript 上保留任何连接字符串根本不是一个好习惯。不要在客户端保留任何敏感的东西。调用服务器端验证并进行处理。
function validateForm()
{
if(document.frm.username.value=="srinu")
{
$.ajax({
type: 'GET',
url: 'validateuser?username=document.frm.username.value' + '&Pwd=' + document.frm.userpassword.value,
success: function (data) {
if (data=='Y')
alert('Valid User');
else
alert('Invalid User');
}, cache: false,
error: function (xhr, ajaxOptions, thrownError) {
alert('failed.');
}
});
}
}
回答by Vinoth Krishnan
@user2773010 Glad to help, not for entire project. You need to think about how to implement the following snippit as per your requirements.
@ user2773010 很高兴为您提供帮助，而不是为整个项目提供帮助。您需要考虑如何根据您的要求实现以下代码段。
String userName = request.getParameter("user");
String password = request.getParameter("pass");
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver") ;
con = DriverManager.getConnection("jdbc:odbc:library", "administrator", "");
stat = con.createStatement();
System.out.println("user Connected");
rs = stat.executeQuery("Select * FROM User_Master");
while(rs.next())
{
String un = rs.getString(5);
String Pwd = rs.getString(6);
if(un.equals(userName) && Pwd.equals(password))
{
session.setAttribute("username",un);
String des = "http://localhost:8080/Final_Review/review/homeuser.jsp";
response.sendRedirect(response.encodeRedirectURL(des));
break;
}
/* else
{
response.sendRedirect(response.encodeRedirectURL("http://localhost:8080/Final_Review/review/ErrorPage.jsp"));
}*/
}
stat.close();
con.close();
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
catch(SQLException se)
{
System.out.println(se);
}
}
