extending PDO class

Question

Below is the db connection class I came out with so far, but I am going to improve it by extending the PDO class itself,

Answer 1

$dsn is data source name. It handles your hostname for you. You use it like this:

$dsn = 'mysql:dbname=YOUR_DB_NAME;host=YOUR_HOSTNAME'

With the line $this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); You have set exceptions to be raised when errors occur (which I like), so in your extended class you can handle errors in exception handlers. If you had a method called getAssoc in your extended PDO class then it would look like this:

/// Get an associative array of results for the sql.
public function getAssoc($sql, $params=array())
{
   try
   {
      $stmt = $this->prepare($sql);
      $params = is_array($params) ? $params : array($params);
      $stmt->execute($params);

      return $stmt->fetchAll(PDO::FETCH_ASSOC);
   }
   catch (Exception $e)
   {
      // Echo the error or Re-throw it to catch it higher up where you have more
      // information on where it occurred in your program.
      // e.g echo 'Error: ' . $e->getMessage(); 

      throw new Exception(
            __METHOD__ . 'Exception Raised for sql: ' . var_export($sql, true) .
            ' Params: ' . var_export($params, true) .
            ' Error_Info: ' . var_export($this->errorInfo(), true),
            0,
            $e);
   }
}

Answer 2

I would concentrate on what the class needs to do rather than trying to re write the PDO. I had the same idea because i though it would simplify and stream line the code but it doesn't. You end up spending more time working out how to indirectly interface with the PDO.