What are the common reasons for a PHP script to return a blank page when executing a MySQL query generated from user input?

The most common reasons for a PHP script to return a blank page when executing a MySQL query generated from user input are syntax errors in the query, improper handling of user input (such as not escaping special characters), or database connection issues. To solve this issue, always sanitize and validate user input before using it in a query, check for errors in the query execution, and ensure that the database connection is properly established. 

<?php
// Assuming $conn is the database connection object

// Sanitize and validate user input
$user_input = mysqli_real_escape_string($conn, $_POST['user_input']);

// Build the query using the sanitized user input
$query = "SELECT * FROM table_name WHERE column_name = '$user_input'";

// Execute the query and check for errors
$result = mysqli_query($conn, $query);
if(!$result) {
    die("Error executing query: " . mysqli_error($conn));
}

// Process the query result
while($row = mysqli_fetch_assoc($result)) {
    // Output or process the data
}

// Close the connection
mysqli_close($conn);
?>

Keywords

PHP MySQL user input SQL injection error handling

Related Questions