What common mistakes can lead to issues with text fields in PHP forms?

Common mistakes that can lead to issues with text fields in PHP forms include not properly sanitizing user input, not validating input length, and not escaping special characters before storing or displaying the data. To solve these issues, always sanitize user input using functions like htmlspecialchars(), validate input length using functions like strlen(), and escape special characters using functions like mysqli_real_escape_string() before interacting with a database.

// Sanitize user input
$text_field = htmlspecialchars($_POST['text_field']);

// Validate input length
if(strlen($text_field) < 50){
    // Proceed with storing or displaying the data
}

// Escape special characters before storing in database
$escaped_text_field = mysqli_real_escape_string($conn, $text_field);
// Insert into database
$query = "INSERT INTO table_name (text_field) VALUES ('$escaped_text_field')";
mysqli_query($conn, $query);