Connect Your Website to Databases with PHP and MySQL

To use PHP and MySQL to connect a website and a database, you need to follow the following steps: Install PHP and MySQL on the Web server. Establish a MySQL database and user account. Use PHP's MySQLi extension to establish a database connection. Prepare the SQL query. Execute the query. Process the query results. Close the connection

Use PHP and MySQL to connect the website and the database

In this article, we will learn how to use PHP and MySQL to connect the website and the database. We'll explore the MySQLi extension for PHP, which provides an easy and powerful way to interact with MySQL databases.

Prerequisites

• Install PHP and MySQL on your web server
• Existing MySQL database and user account

Connecting to a MySQL database

It’s very easy to establish a database connection using PHP’s MySQLi extension. Here is a sample code:

<?php
$hostname = "localhost";
$username = "username";
$password = "password";
$database = "database_name";

// 创建 MySQL 连接
$mysqli = new mysqli($hostname, $username, $password, $database);

// 检查连接是否成功
if ($mysqli->connect_errno) {
    echo "无法连接到数据库: " . $mysqli->connect_error;
    exit();
}
?>

Practical case: reading data

Now that we are connected to the database, let's write a simple script to read it data. Here is an example:

<?php
// 创建 MySQL 连接
$mysqli = new mysqli($hostname, $username, $password, $database);

// 准备一个查询
$query = "SELECT * FROM users";

// 执行查询
$result = $mysqli->query($query);

// 检查查询是否成功
if (!$result) {
    echo "查询失败: " . $mysqli->error;
    exit();
}

// 提取并显示查询结果
while ($row = $result->fetch_assoc()) {
    echo $row['id'] . " " . $row['name'] . "<br>";
}

// 关闭结果集
$result->close();

// 关闭连接
$mysqli->close();
?>

Practical Case: Writing Data

Next, let’s learn how to use PHP to write data to a MySQL database. Here is an example:

<?php
// 创建 MySQL 连接
$mysqli = new mysqli($hostname, $username, $password, $database);

// 准备一个插入查询
$query = "INSERT INTO users (name, email) VALUES (?, ?)";

// 创建一个预处理语句对象
$stmt = $mysqli->prepare($query);

// 绑定参数
$stmt->bind_param("ss", $name, $email);

// 设置参数
$name = "John Doe";
$email = "john.doe@example.com";

// 执行准备好的语句
$stmt->execute();

// 获取查询结果
$result = $stmt->get_result();

// 检查查询是否成功
if (!$result) {
    echo "查询失败: " . $stmt->error;
    exit();
}

// 关闭准备好的语句
$stmt->close();

// 关闭连接
$mysqli->close();
?>

Conclusion

Connecting a website to a database using PHP and MySQL is a relatively simple process. By using the MySQLi extension, you can easily interact with the MySQL database, read and write data.

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