PHP、Java、C++大神教你建站基础代码

在当今这个信息化时代，网站已经成为了企业和个人展示自己的窗口，掌握一门或多门编程语言，可以帮助我们快速搭建网站，本文将分别介绍PHP、Java和C++三种编程语言在建站过程中的基本代码。

一、PHP基础代码

1. 连接数据库

```php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

// 创建连接

$conn = new mysqli($servername, $username, $password, $dbname);

// 检测连接

if ($conn->connect_error) {

die("连接失败： " . $conn->connect_error);

?>

```

2. 获取用户输入数据并插入数据库

```php

if ($_SERVER["REQUEST_METHOD"] == "POST") {

$name = $_POST["name"];

$email = $_POST["email"];

$message = $_POST["message"];

$sql = "INSERT INTO messages (name, email, message) VALUES ('$name', '$email', '$message')";

if ($conn->query($sql) === TRUE) {

echo "新记录插入成功";

} else {

echo "Error: " . $sql . "
" . $conn->error;

}

?>

```

3. 从数据库中读取数据并显示在网页上

```php

$sql = "SELECT id, name, email FROM messages";

$result = $conn->query($sql);

?>

Messages

num_rows > 0): ?>fetch_assoc()): ?>

ID	Name	Email

No messages found.close(); ?>

```

二、Java基础代码(以JSP为例)

1. 建立数据库连接(这里以MySQL为例)

```java

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp2.BasicDataSourceFactory;

import org.apache.commons.dbcp2.BasicDataSource;

import com.mysql.cj.jdbc.MysqlDataSource; // 需要添加MySQL Connector/J依赖包

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

```