What are some common mistakes or misconceptions when using mysqli_real_escape_string in PHP?

One common mistake when using mysqli_real_escape_string in PHP is forgetting to establish a connection to the database before calling the function. Another mistake is not properly escaping special characters in the SQL query, leading to potential SQL injection vulnerabilities. To solve this, always ensure you have an active database connection and properly escape user input before using it in SQL queries. 

// Establish a connection to the database
$connection = mysqli_connect('localhost', 'username', 'password', 'database');

// Check if the connection is successful
if (!$connection) {
    die("Connection failed: " . mysqli_connect_error());
}

// Escape user input before using it in an SQL query
$user_input = mysqli_real_escape_string($connection, $_POST['user_input']);

// Use the escaped input in your SQL query
$query = "SELECT * FROM users WHERE username='$user_input'";
$result = mysqli_query($connection, $query);

// Remember to close the connection when done
mysqli_close($connection);

Keywords

mysqli_real_escape_string SQL injection data sanitization prepared statements security vulnerabilities

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