This question already has answers here:
How to get the insert ID in JDBC?
（12个答案）
5年前关闭。
如何使用JSP Servlet从数据库获取ID。这是我的JSP Servlet代码，我需要通过警报消息框显示ID的代码，在数据库中，我将ID作为数据库中的自动增量给出。我最近两天都在尝试这个。
将记录插入db后，如何从数据库中获取ID？
请帮我显示一个ID，例如“注册是suss-您的id是.........”
}
其中ps是PreparedStatement，您可以从ResultSet对象中检索键。
（12个答案）
5年前关闭。
如何使用JSP Servlet从数据库获取ID。这是我的JSP Servlet代码，我需要通过警报消息框显示ID的代码，在数据库中，我将ID作为数据库中的自动增量给出。我最近两天都在尝试这个。
将记录插入db后，如何从数据库中获取ID？
请帮我显示一个ID，例如“注册是suss-您的id是.........”
package controller;
import java.io.IOException;
import java.io.PrintWriter;
javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
//import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
import javax.servlet.*;
/**
* Servlet implementation class Register
*/
@WebServlet("/Register")
public class Register extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 2945154063362413961L;
/**
* @see HttpServlet#HttpServlet()
*/
public Register() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
PrintWriter pw = response.getWriter();
/*String fname=request.getParameter("firstname");
String lname=request.getParameter("lastname");*/
//pw.println("Firstname is" +fname);
//pw.println("Firstname is" +lname);
/*System.out.println("first=="+fname);
System.out.println("last==="+lname);
*/
//String connectionURL = "jdbc:mysql://127.0.0.1:3306/newData";// newData is the database
//Connection connection;
Connection conn=null;
String url="jdbc:mysql://localhost:3306/";
String dbName="Registrationform";
String driver="com.mysql.jdbc.Driver";
String dbUserName="root";
String dbPassword="root";
try{
String Fname = request.getParameter("firstname");
String Lname = request.getParameter("lastname");
String dob = request.getParameter("dob");
String email= request.getParameter("email");
Class.forName(driver).newInstance();
System.out.println("welcome");
conn = DriverManager.getConnection(url+dbName,dbUserName, dbPassword);
System.out.println("Connection created");
PreparedStatement pst =(PreparedStatement) conn.prepareStatement("insert into event (firstname,lastname,dob,email) values(?,?,?,?)");//try2 is the name of the table
pst.setString(1,Fname);
pst.setString(2,Lname);
pst.setString(3,dob);
pst.setString(4,email);
int i = pst.executeUpdate();
System.out.println("Query updated");
PreparedStatement pstr =(PreparedStatement) conn.prepareStatement("select * from event(id);");//try2 is the name of the table
//conn.commit();
String msg=" ";
if(i!=0){
msg="You Are Succesfully Register For The Event Meet";
//alert("You Are Succesfully Register For The E;vent Meet")
// response.sendRedirect("reg.jsp");
pw.println("<font size='4' color=black font family = times new roman >" + msg + "</font>");
}
else{
msg="Failed to insert the data";
pw.println("<font size='4' color=black font family = times new roman >" + msg + "</font>");
}
pst.close();
}
catch (Exception e){
pw.println(e);
}
}
}
java script code
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link rel="stylesheet" type="text/css" href="reg.css">
<title>Event Registration From</title>
</head>
<body class= "main">
<script type="text/javascript">
function register(registerform)
{
if(registerform.firstname.value == "") {
alert("Please enter your Firstname");
registerform.firstname.focus();
return false;
}
if(registerform.lastname.value == "") {
alert("Please enter your Lastname");
registerform.lastname.focus();
return false;
}
if(registerform.dob.value == "") {
alert("Please select your DOB");
registerform.dob.focus();
return false;
}
if(registerform.email.value == "") {
alert("Please enter your Email-id");
registerform.email.focus();
return false;
}
/* var x=document.forms["form"]["email_id"].value;
var atpos=x.indexOf("@");
var dotpos=x.lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
{
alert("Not a valid e-mail address");
return false;
} */
return true;
}
</script>
<form name="registerform" action ="Register" method = "post">
<div>
<h3> Event Registration Form </h3>
<div>
<label for ="first" class ="label" > First Name </label>
<input type="text" id="first" name="firstname" class="text" />
</div>
<div>
<label for ="last" class ="label">Last Name</label>
<input type="text" id="last" name="lastname" class="text">
</div>
<div>
<label for ="dob" class ="label">Date Of Birth </label>
<input type="text" id="dob" name="dob" class="text">
</div>
<div>
<label for ="email" class ="label">Email_Id</label>
<input type="text" id="email" name="email" class="text">
</div>
<div><input type="submit" value ="submit" class="button" onclick="register(registerform)"></div>
</div></form>
</body>
</html>
最佳答案
您可以使用MySQL尝试类似的方法：
PreparedStatement ps = connection.prepareStatement(query, PreparedStatement.RETURN_GENERATED_KEYS);
// Get generated key.
ps.executeUpdate();
ResultSet rs = ps.getGeneratedKeys();
if (rs.next()) {
int key = rs.getInt(1);
}
其中ps是PreparedStatement，您可以从ResultSet对象中检索键。
关于java - 将记录插入db后，如何从数据库中获取id ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/23827120/