khanat-opennel-code/code/ryzom/tools/server/ryzom_ams/ams_lib/autoload/dblayer.php

<?php
/**
* Handles the database connections. It uses PDO to connect to the different databases. It will use the argument of the constructor to setup a connection to the database 
* with the matching entry in the $cfg global variable.
* @author Daan Janssens, mentored by Matthew Lagoe
* 
*/
class DBLayer{
    
    private $PDO; /**< The PDO object, instantiated by the constructor */ 
    
    /**
    * The constructor.
    * Instantiates the PDO object attribute by connecting to the arguments matching database(the db info is stored in the $cfg global var)
    * @param $db String, the name of the databases entry in the $cfg global var.
    */
    function __construct($db, $dbn = null)
    {
        if ($db != "install"){
        
            global $cfg;
            $dsn  = "mysql:";
            $dsn .= "host=".   $cfg['db'][$db]['host'].";";
            $dsn .= "dbname=". $cfg['db'][$db]['name'].";";
            $dsn .= "port=".   $cfg['db'][$db]['port'].";";
        
            $opt = array(
                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
            );
            $this->PDO = new PDO($dsn,$cfg['db'][$db]['user'],$cfg['db'][$db]['pass'], $opt);
        } else {
            global $cfg;
            $dsn  = "mysql:";
            $dsn .= "host=".   $cfg['db'][$dbn]['host'].";";
            $dsn .= "port=".   $cfg['db'][$dbn]['port'].";";
        
            $opt = array(
                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
            );
            $this->PDO = new PDO($dsn,$_POST['Username'],$_POST['Password'], $opt);
        }

    }
    
    /**
    * execute a query that doesn't have any parameters
    * @param $query the mysql query
    * @return returns a PDOStatement object 
    */
    public function executeWithoutParams($query){
        $statement = $this->PDO->prepare($query);
        $statement->execute();
        return $statement;
    }
    
    /**
    * execute a query that has parameters
    * @param $query the mysql query
    * @param $params the parameters that are being used by the query
    * @return returns a PDOStatement object 
    */
    public function execute($query,$params){
        $statement = $this->PDO->prepare($query);
        $statement->execute($params);
        return $statement;
    }
    
   /**
    * execute a query (an insertion query) that has parameters and return the id of it's insertion
    * @param $query the mysql query
    * @param $params the parameters that are being used by the query
    * @return returns the id of the last inserted element.
    */
    public function executeReturnId($tb_name,$data){		
        $field_values =':'. implode(',:', array_keys($data));
        $field_options = implode(',', array_keys($data));		
        try{
            $sth = $this->PDO->prepare("INSERT INTO $tb_name ($field_options) VALUE ($field_values)");
            foreach ($data as $key => $value )
            {       	
                $sth->bindValue(":$key", $value);
            }
            $this->PDO->beginTransaction();
            //execution
            $sth->execute();
            $lastId =$this->PDO->lastInsertId();
            $this->PDO->commit();
        }catch (Exception $e)
        {
            //for rolling back the changes during transaction
            $this->PDO->rollBack();
            throw new Exception("error in inseting");
        }
	return $lastId;
    }
     
     
    /**
     * 
     * Select function using prepared statement
     * @param string $tb_name Table Name to Select
     * @param array $data Associative array
     * @param string $where where to select
     * @return statement object
     */
    public function selectWithParameter($param, $tb_name, $data, $where)
    {	
        try{        	
            $sth = $this->PDO->prepare("SELECT $param FROM $tb_name WHERE $where");
            $this->PDO->beginTransaction();	
            $sth->execute($data);            
            $this->PDO->commit();	
        }catch(Exception $e)
        {
           $this->PDO->rollBack();
           throw new Exception("error selection");
               return false;
        }        
        return $sth;
    }
       
    /**
     * 
     * Select function using prepared statement
     * @param string $tb_name Table Name to Select
     * @param array $data Associative array
     * @param string $where where to select
     * @return statement object
     */
    public function select($tb_name, $data ,$where)
    {	
        try{        	
            $sth = $this->PDO->prepare("SELECT * FROM $tb_name WHERE $where");
			$this->PDO->beginTransaction();	
            $sth->execute($data);            
            $this->PDO->commit();	
        }catch(Exception $e)
        {
           $this->PDO->rollBack();
            throw new Exception("error selection");
               return false;
        }        
        return $sth;
    }

    /**
     *
     * Update function with prepared statement
     * @param string $tb_name name of the table
     * @param array $data associative array with values
     * @param string $where where part
     * @throws Exception error in updating
     */
    public function update($tb_name, $data, $where)
    {
        $field_option_values=null;
        foreach ($data as $key => $value)
        {
            $field_option_values.=",$key".'=:'.$value;
        }
        $field_option_values = ltrim($field_option_values,',');
        try {
            $sth = $this->PDO->prepare("UPDATE $tb_name SET $field_option_values WHERE $where ");

            foreach ($data as $key => $value)
            {
                $sth->bindValue(":$key", $value);
            }
			$this->PDO->beginTransaction();
            $sth->execute();
            $this->PDO->commit();
        }catch (Exception $e)
        {
            $this->PDO->rollBack();
            throw new Exception('error in updating');
        }
    }
    /**
     *
     * insert function using prepared statements
     * @param string $tb_name Name of the table to insert in
     * @param array $data Associative array of data to insert
     */
     
    public function insert($tb_name, $data)
    {
        $field_values =':'. implode(',:', array_keys($data));
        $field_options = implode(',', array_keys($data));		
        try{
            $sth = $this->PDO->prepare("INSERT INTO $tb_name ($field_options) VALUE ($field_values)");
            foreach ($data as $key => $value )
            {
                $sth->bindValue(":$key", $value);
            }
            $this->PDO->beginTransaction();
            //execution
            $sth->execute();
            $this->PDO->commit();

        }catch (Exception $e)
        {
            //for rolling back the changes during transaction
            $this->PDO->rollBack();
            throw new Exception("error in inseting");
        }
    }

    /**
     *
     * Delete database entery using prepared statement
     * @param string $tb_name
     * @param string $where
     * @throws error in deleting
     */
    public function delete($tb_name, $where)
    {
        try {
            $sth = $this->prepare("DELETE FROM $tb_name WHERE $where");
            $this->PDO->beginTransaction();
            $sth->execute();
            $this->PDO->commit();
        }
        catch (Exception $e)
        {
            $this->rollBack();
            throw new Exception("error in deleting");
        }

    } 
}