PHP mysqli_stmt::bind_param() Method: Usage and Examples

Binds PHP variables by reference to a prepared MySQLi statement's placeholders.

The examples focus on the operation itself, including the important distinction: PDOStatement::execute accepts parameter arrays instead of mysqli's reference binding.

What It Does

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

Syntax and Return Value

mysqli_stmt::bind_param(string $types, mixed &$var, mixed &...$vars): bool

The displayed signature describes the API or identifies any correction or optional dependency. When a parameter is optional, supply it only when the task requires it.

Example 1: Basic Use

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query. The i type markers correspond to two integer variables passed by reference.

<?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');
$statement = $mysqli->prepare('SELECT email FROM users WHERE id = ? AND active = ?');
$selectedId = 7;
$active = 1;
$statement->bind_param("ii", $selectedId, $active);
$statement->execute();
$row = $statement->get_result()->fetch_assoc();
echo $row["email"] ?? "not found";

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

Example 2: Checking Behavior

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query. The i type markers correspond to two integer variables passed by reference.

<?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');
$statement = $mysqli->prepare('SELECT email FROM users WHERE id = ? AND active = ?');
$selectedId = 12;
$active = 1;
$statement->bind_param("ii", $selectedId, $active);
$statement->execute();
$row = $statement->get_result()->fetch_assoc();
echo $row["email"] ?? "not found";

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

Example 3: Practical Example

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query. The i type markers correspond to two integer variables passed by reference.

<?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');
$statement = $mysqli->prepare('SELECT email FROM users WHERE id = ? AND active = ?');
$selectedId = 24;
$active = 1;
$statement->bind_param("ii", $selectedId, $active);
$statement->execute();
$row = $statement->get_result()->fetch_assoc();
echo $row["email"] ?? "not found";

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

The type string must match the number of bound variables; use i, d, s or b as appropriate.

This API is supplied by an optional extension that is not installed in the local test runtime, or requires a different PHP version. The example must be verified in a matching environment.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Binds PHP variables by reference to a prepared MySQLi statement's placeholders.
• The type string must match the number of bound variables; use i, d, s or b as appropriate.
• PDOStatement::execute accepts parameter arrays instead of mysqli's reference binding.

Use mysqli_stmt::bind_param when its documented behavior matches the problem. Test the relevant edge cases in your own runtime before deploying it.