How Can I Effectively Use mysqli Prepared Statements in PHP?

Understanding and Implementing mysqli Prepared Statements

If you are facing difficulty in using mysqli prepared statements, it's essential to identify the root cause of the issue. Let's analyze the code you provided and address the errors encountered.

In your code, you are attempting to execute a prepared statement without binding parameters. According to the mysqli::prepare documentation, parameter markers in prepared statements need to be bound to application variables before execution. To resolve this issue, you should use mysqli_stmt_bind_param() to bind the parameters before executing the statement.

Regarding your question about using mysqli for prepared statements, yes, mysqli is the recommended extension for PHP and is widely supported. It offers robust functionality for handling SQL queries, including prepared statements, data binding, and transaction management.

Complete Example: Connection, Insertion, and Selection with Error Handling

Here's a complete example that demonstrates the use of prepared statements with mysqli, including connection, insertion, and selection with error handling:

<?php
// Establish a connection to the database
$mysqli = new mysqli("localhost", "root", "root", "test");
if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;
    exit();
}

// Prepare insert statement
$sql = "INSERT INTO users (name, age) VALUES (?, ?)";
$stmt = $mysqli->prepare($sql);
if (!$stmt) {
    echo "Failed to prepare statement: " . $mysqli->error;
    exit();
}

// Bind parameters
$name = 'John Doe';
$age = 30;
$stmt->bind_param("si", $name, $age);

// Execute insertion
if (!$stmt->execute()) {
    echo "Failed to execute insertion: " . $stmt->error;
    exit();
}

// Prepare select statement
$sql = "SELECT * FROM users WHERE name = ?";
$stmt = $mysqli->prepare($sql);
if (!$stmt) {
    echo "Failed to prepare statement: " . $mysqli->error;
    exit();
}

// Bind parameter
$name = 'John Doe';
$stmt->bind_param("s", $name);

// Execute selection
if (!$stmt->execute()) {
    echo "Failed to execute selection: " . $stmt->error;
    exit();
}

// Get result
$result = $stmt->get_result();
if (!$result) {
    echo "Failed to get result: " . $stmt->error;
    exit();
}

// Iterate through the result and display data
while ($row = $result->fetch_assoc()) {
    echo "ID: " . $row['id'] . ", Name: " . $row['name'] . ", Age: " . $row['age'] . "\n";
}

// Close the statement and connection
$stmt->close();
$mysqli->close();
?>

This code establishes a connection to the database, prepares insert and select statements, binds parameters, executes queries, and handles errors accordingly. It showcases the complete workflow of using prepared statements with mysqli.

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