Understanding the 'mysqli' Extension in PHP: MySQL Improved

The 'mysqli' extension in PHP stands for "MySQL Improved". This is an advanced version of PHP's original MySQL extension, which provides an efficient and convenient interface to the MySQL database. It is designed to work with MySQL version 4.1.13 or newer, offering various benefits over the older mysql extension such as prepared statements, multiple statements, transactions, and more.

Practical Application of 'mysqli' extension

1. Incrementing Efficiency and Security with Prepared Statements: A major benefit of using the mysqli extension is that it supports prepared statements. These are a way to write SQL code, which separates the instruction from the data. It can increase efficiency and security, as it allows you to prepare an SQL statement once and execute it multiple times with different values.

Here is a simple example to illustrate:

$stmt = $mysqli->prepare("INSERT INTO Products (ProductName, Price) VALUES (?, ?)");
$stmt->bind_param("si", $product_name, $price);

$product_name = "Apple";
$price = 1;
$stmt->execute();

$product_name = "Orange";
$price = 2;
$stmt->execute();

2. Executing Multiple Statements: mysqli allows the execution of multiple SQL statements with one call to mysqli::multi_query. It can significantly increase the performance when executing many queries.

$query  = "SELECT count(*) FROM Products;";
$query .= "INSERT INTO Products(ProductName, Price) VALUES ('Banana', 3)";

if ($mysqli->multi_query($query)) {
    do {
        if ($result = $mysqli->store_result()) {
            while ($row = $result->fetch_row()) {
                printf("%s\n", $row[0]);
            }
            $result->free();
        }
    } while ($mysqli->next_result());
}

Best Practices When Using 'mysqli' Extension

When using the mysqli extension, it's important to always check for successful connection to the database. This can be done using the mysqli_connect_error function, which will return a string description of the last connect error.

$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'my_db');

if ($mysqli->connect_error) {
    die('Connect Error (' . $mysqli->connect_errno . ') '
            . $mysqli->connect_error);
}

Another good practice involves using the real escape string function (mysqli_real_escape_string) for all variables included in SQL queries. This helps to prevent SQL injection attacks by escaping any special characters in a string.

Remember, despite the significant improvements brought by the 'mysqli' extension, it's also recommended to consider other options like PDO (PHP Data Objects) depending on your specific project needs and circumstances. It is crucial to select the appropriate tool that aligns with your project structure, database type, and overall requirements.