Question

how to insert special characters into a database(MySQL) like

Registered symbol ( ® ) OR
Copyright sign ( © ) OR
Trade Mark sign ( ™ )

Also I want to display as original on the html page.

What I have to do in both side (front end and back end), please elaborate

Which function is more effective?

Method 1:

$_GET = array_map('trim', $_GET);
$_POST = array_map('trim', $_POST);
 
if(get_magic_quotes_gpc()){
  $_GET = array_map('stripslashes', $_GET);
  $_POST = array_map('stripslashes', $_POST);  
  
  $_GET = array_map('strip_tags', $_GET);
  $_POST = array_map('strip_tags', $_POST);  
 }
 else{
  $_GET = array_map('mysql_real_escape_string', $_GET);
  $_POST = array_map('mysql_real_escape_string', $_POST);   
 }

Method 2:

  foreach ($_POST as $key=>$value){
        if (!get_magic_quotes_gpc()) {
          return addslashes(htmlentities(strip_tags($value),ENT_QUOTES,'UTF-8'));
          } 
          else {
             return htmlentities(strip_tags($value),ENT_QUOTES,'UTF-8');
          }
  }

I am a bit confused what is the difference between

htmlentities() and htlspecialchars(), and which one i have to use?

which function should be used addslashes() or stripslashes() when insert into database?

Answer 1

Just simply add those symbols to your text, and execute it as SQL query:

INSERT INTO tbl_name VALUES ("Here's my text: ©®");

When you want to display it one the website don’t do anything with these symbols (but remember to escape at least <, >, & (using htmlspecialchars()) cause those has special meaning in XML/SGML (HTML) documents)

PS. Also remember to escape text passed to SQL query using mysql_real_escape_string() to avoid any SQL Injection problems. If your server has magic_quotes_gpc enabled disable it or at least filter your GET/POST/COOKIE data to its raw value. You should always consciously escape values.

EDIT:

According to your comment… I don’t remember whether magic_quotes_gpc are enabled by default but you can easily undone magic quotes effect. Just on the very beginning of your PHP code add something like this:

if (get_magic_quotes_gpc()) {
  array_walk_recursive($_GET, 'stripslashes');
  array_walk_recursive($_POST, 'stripslashes');
  array_walk_recursive($_COOKIE, 'stripslashes');
}

Now each GPC value should be always raw – without quotes – so you have to escape it manually before passing any variable into query.