Study the underlying development principles of PHP: caching technology and data storage

Study on the underlying development principles of PHP: caching technology and data storage

Introduction:
PHP is a server-side scripting language widely used in Web development. The underlying development principles are a very important research topic for program developers. In PHP development, performance improvement is a key factor, and caching technology and efficient data storage are important means to optimize performance. This article will introduce caching technology and data storage in the underlying development principles of PHP, and illustrate it through code examples.

1. Caching technology

Cache technology is one of the common means to improve system performance. It saves calculation results, database query results, etc. in memory to avoid repeated calculations and queries, thereby Improve access speed. In the underlying development of PHP, we can use the caching technology provided by Zend Engine to speed up the running of the program. Zend OPCache is a caching technology for PHP that can save PHP code in memory after compilation to avoid recompiling PHP code every time it is executed.

The following is a simple code example that demonstrates how to use Zend OPCache for caching:

<?php
$opcache_enabled = function_exists('opcache_compile_file');

if ($opcache_enabled) {
    $file = 'test.php';
    if (opcache_is_script_cached($file)) {
        echo 'From cache: ';
    } else {
        echo 'Not from cache: ';
        opcache_compile_file($file);
    }
} else {
    echo 'Zend OPCache not enabled.';
}
?>

In the above code, first check whether Zend OPCache is available, and if available, determine whether the script has been Cache, if it has been cached, it will be read directly from the cache, otherwise the script will be compiled and then cached. This avoids recompiling the script for each request and improves the running efficiency of the program.

2. Data storage

In PHP development, data storage is a very important link. Reasonable selection of data storage methods can improve system performance. In underlying development, we often use databases to store and manage data. MySQL is one of the most commonly used relational databases at present. It provides efficient data storage and query functions.

The following is a simple code example that demonstrates how to use PHP to connect to a MySQL database and perform data storage and query:

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// 数据存储
$sql = "INSERT INTO users (name, age, email) VALUES ('John Doe', 25, 'john@example.com')";
if ($conn->query($sql) === TRUE) {
    echo "Data stored successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

// 数据查询
$sql = "SELECT * FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "Name: " . $row["name"]. " - Age: " . $row["age"]. " - Email: " . $row["email"]. "<br>";
    }
} else {
    echo "No data found";
}

// 关闭连接
$conn->close();
?>

In the above code, a MySQL connection is first created and checked Whether the connection is successful. Then perform data storage and store the data into the database by executing SQL statements. Then perform data query and obtain the data in the database by executing SQL statements. Finally close the MySQL connection.

Summary:
By learning caching technology and data storage principles, we can better understand the underlying development principles of PHP and be able to optimize the performance of the program. Caching technology can avoid repeated calculations and queries and improve program running speed; while efficient data storage can ensure data security and consistency. Therefore, an in-depth study of the underlying development principles of PHP is very beneficial for us to write high-performance PHP programs.

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