PHP MySQLi Prepared Statements with Typed Parameters

MySQLi bind_param maps types i, d, s and b to server-side statement parameters.

The examples focus on the operation itself, including the important distinction: PDO bindValue and PDO execute use a different parameter API.

What It Does

Use the examples below to observe the behavior on a small dataset before extending it to application code.

Before You Start

The examples use PHP 8.2+ features where shown. Database snippets require the corresponding PDO driver, demo tables, and credentials configured outside source code.

Example 1: Basic Use

bind_param receives variables by reference and a type character per placeholder.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$id = 3;
$email = '[email protected]';
$stmt = $mysqli->prepare("UPDATE users SET email = ? WHERE id = ?");
$stmt->bind_param("si", $email, $id);
$stmt->execute();
echo $stmt->affected_rows;

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Example 2: Checking Behavior

bind_param receives variables by reference and a type character per placeholder.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$id = 8;
$email = '[email protected]';
$stmt = $mysqli->prepare("UPDATE users SET email = ? WHERE id = ?");
$stmt->bind_param("si", $email, $id);
$stmt->execute();
echo $stmt->affected_rows;

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Example 3: Practical Example

bind_param receives variables by reference and a type character per placeholder.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$id = 21;
$email = '[email protected]';
$stmt = $mysqli->prepare("UPDATE users SET email = ? WHERE id = ?");
$stmt->bind_param("si", $email, $id);
$stmt->execute();
echo $stmt->affected_rows;

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Important Behavior and Edge Cases

Type markers must match parameter count; bind_param accepts variables by reference.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• MySQLi bind_param maps types i, d, s and b to server-side statement parameters.
• Type markers must match parameter count; bind_param accepts variables by reference.
• PDO bindValue and PDO execute use a different parameter API.

Use PHP MySQLi Prepared Statements with Typed Parameters when its documented behavior matches the problem. Test the relevant edge cases in your own runtime before deploying it.