PHP / MySQL中的PDO和UTF-8特殊字符？

Question

I am using MySQL and PHP 5.3 and tried this code.

$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$con = mysql_connect("localhost", "root", "");
mysql_set_charset('utf8');
if (!$con)
{
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("kdict", $con);
$sql = "SELECT * FROM `en-kh` where english='a'";
echo $sql;
$result = mysql_query($sql);

while($row = mysql_fetch_array($result))
{
  echo $row['english'] . " </br> " . $row['khmer'];
  echo "<br />";
}
?>

=> I got good UTF-8 render display, well done.

But for now I create a class PDO to keep easy to extend and more easy

 class crud {
     // code..
     public function conn()
     {
         isset($this->username);
         isset($this->password);
         if (!$this->db instanceof PDO)
         {
             $this->db = new PDO($this->dsn, $this->username, $this->password);
             $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
             $this->db->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAMES 'utf8'");   
          }
      }
      /*more code here*/
}



/*** a new crud object ***/
$crud = new crud();
/*** The DSN ***/
$crud->dsn = "mysql:dbname=kdict;host=localhost";

/*** MySQL username and password ***/
$crud->username = 'root';
$crud->password = '';
/*** select all records from table ***/
$records = $crud->rawSelect("SELECT * FROM `en-kh` where english='a'");

/*** fetch only associative array of values ***/
$rows = $records->fetchAll(PDO::FETCH_ASSOC);

/*** display the records ***/
foreach($rows as $row)
{
    foreach($row as $fieldname=>$value)
    {
        echo $fieldname.' = '.$value.'<br />';
    }
    echo '<hr />';
}
?>

But it displays my character something like this '????'

I found this link on Stack Overflow, it looks like the same problem i met Special characters in PHP / MySQL

It looks the same as my problem => I tried to fix it, but I still doesn't work.

$this->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAME'utf8'");

Can anyone tell me what the problem is? How can I correct it?

thanks

Answer 1

You're missing an S : it's SET NAMES and not SET NAME :

$this->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAMES 'utf8'");

You also need to un-comment it of course. Also, PDO::MYSQL_ATTR_INIT_COMMAND can not be set with PDO::setAttribute() after you've established your database connection (the constant name says it all), you've to specify it in the constructor using the $driver_options argument, like this:

$this->db = new PDO($this->dsn, $this->username, $this->password, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"));

An alternative to this is to just execute that very same query immediately after connecting:

$this->db = new PDO($this->dsn, $this->username, $this->password);
$this->db->exec("SET NAMES 'utf8';");

Answer 2

I had the same trouble and found out after trying out 1000000 different options that the default mysql engine still remains MyISAM.

Verifying that InnoDB is the Default Storage Engine as such:

Issue the command SHOW VARIABLES LIKE 'have_innodb'; to confirm that InnoDB is available at all.

Then issue the command SHOW ENGINES; to see all the different MySQL storage engines.

Look for DEFAULT in the InnoDB line and NOT in the MyISAM line. I realized that my provided had a setting preventing me from changing the default engine using SET storage_engine=MYISAM; . In my case, I contacted my provider and was directed to where I could change the option to be able to change the default engine. Hope this helps!

Answer 3

The possible way to insert Special characters using PDO, just follow the these to steps:

1) Set the Attribute to you connection class.

$this->db->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAME'utf8'");

2) Now you can use htmlspecialchars while query creation and insertion to database:

$ShortDescription   = htmlspecialchars($_POST['ShortDescription'], ENT_QUOTES);
$LongDescription    = htmlspecialchars($_POST['LongDescription'],ENT_QUOTES);

And it will work fine.

Answer 4

I suggest always connecting to a database via PDO.

Below is a sample code;

<?php

class connMysql {

    protected static $instance;
    private static $database_type = "mysql";    
    private static $hostname = "localhost";
    private static $user = “database_user”;
    private static $password = “database_user_password”;
    private static $database_name = “your_database”;

    private static $persistent = false;

    private function __construct() {

        try {
            self::$instance = new \PDO(self::$database_type . ":host=" . self::$hostname . ";dbname=" . self::$database_name
                    , self::$user
                    , self::$password
                    , array(
                \PDO::ATTR_PERSISTENT => self::$persistent,
                \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
                \PDO::ATTR_DEFAULT_FETCH_MODE => \PDO::FETCH_ASSOC,
                \PDO::ATTR_STRINGIFY_FETCHES => true,
                \PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"
            ));
        } catch (PDOException $e) {
            echo "Connection Error: " . $e->getMessage();
        }
    }

    public static function getInstance() {
        if (!self::$instance) {
            new connMysql();
        }

        return self::$instance;
    }

    public static function close() {
        self::$instance = null;
    }

}