PDO Common Class Library_PHP Tutorial

1. Db.class.php

// Connect to database
class Db {
static public function getDB() {
         try {
                $pdo = new PDO(DB_DSN, DB_USER, DB_PWD);
                  $pdo->setAttribute(PDO::ATTR_PERSISTENT, true); // Set the database connection to a persistent connection
                 $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // Setup throws an error
                  $pdo->setAttribute(PDO::ATTR_ORACLE_NULLS, true); // Set when the string is empty, it is converted to NULL in SQL
                  $pdo->query('SET NAMES utf8'); // Set database encoding
           } catch (PDOException $e) {
                       exit('Database connection error, error message:'. $e->getMessage());
         } 
          return $pdo;
}  
}
?>
//Connect to database
class Db {
static public function getDB() {
try {
$pdo = new PDO(DB_DSN, DB_USER, DB_PWD);
$pdo->setAttribute(PDO::ATTR_PERSISTENT, true); //Set the database connection as a persistent connection
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // Set throw error
$pdo->setAttribute(PDO::ATTR_ORACLE_NULLS, true); //Set when the string is empty, it is converted to SQL NULL
$pdo->query('SET NAMES utf8'); // Set database encoding
} catch (PDOException $e) {
exit('Database connection error, error message:'. $e->getMessage());
}
return $pdo;
}
}
?>
2. Model.class.php

//Operation SQL
class Model {
/**
* SQL addition, deletion and modification operations, return the number of affected rows
* @param string $sql
* @return int
​​*/
Public function aud($sql) {
         try {
               $pdo = Db::getDB();
$row = $pdo->exec($sql);
           } catch (PDOException $e) {
exit($e->getMessage());
         } 
         return $row;
}  
       
/**
* Return all data, return PDOStatement object
* @param string $sql
* @return PDOStatement
​​*/
Public function getAll($sql) {
         try {
               $pdo = Db::getDB();
                 $result = $pdo->query($sql);
               return $result;
           } catch (PDOException $e) {
exit($e->getMessage());
         } 
}  
}
?>