system/classes/db.php

<?php
namespace Habari;

class DB extends Singleton
{
  private $connection = null;

  protected static function instance()
  {
    return self::getInstanceOf( __CLASS__ );
  }

  public static function connect()
  {
    /*
      if connection has been instantiated (ie: not null), check if is already connected
    */
    if ( null != DB::instance()->connection ) {
      if ( (func_num_args() == 0) && false != DB::instance()->connection->is_connected() ) {
        return true;
      }
    }

    if ( func_num_args() > 0 ) {
      $connect_string = func_get_arg( 0 );
      $db_user = func_get_arg( 1 );
      $db_pass = func_get_arg( 2 );
    }
    else {
      /* We use the config.php variables */
      $connect_string = Config::get( 'db_connection' )->connection_string;
      $db_user = Config::get( 'db_connection' )->username;
      $db_pass = Config::get( 'db_connection' )->password;
    }
    DB::instance()->connection = DatabaseConnection::ConnectionFactory( $connect_string );
    if ( null != DB::instance()->connection ) {
      return DB::instance()->connection->connect( $connect_string, $db_user, $db_pass );
    }
    else {
      // do some error handling here. The connect string does not have a corresponding DB connection object
      print _t( 'Panic! No database connection class appears to be found for the connection string specified. Please check config.php' );
    }
  }

  public static function disconnect()
  {
    if ( null == DB::instance()->connection ) {
      return true;
    }

    return DB::instance()->connection->disconnect();
  }

  public static function table( $name )
  {
    return DB::instance()->connection->table( $name );
  }

  public static function register_table( $name )
  {
    DB::instance()->connection->register_table( $name );
  }

  public static function set_fetch_mode( $mode )
  {
    DB::instance()->connection->set_fetch_mode( $mode );
  }

  public static function set_fetch_class( $class_name )
  {
    DB::instance()->connection->set_fetch_class( $class_name );
  }

  public static function exec( $query )
  {
    return DB::instance()->connection->exec( $query );
  }

  public static function query( $query, $args = array() )
  {
    return DB::instance()->connection->query( $query, $args );
  }

  public static function execute_procedure( $procedure, $args = array() )
  {
    return DB::instance()->connection->execute_procedure( $procedure, $args );
  }

  public static function begin_transaction()
  {
    DB::instance()->connection->begin_transaction();
  }

  public static function rollback()
  {
    DB::instance()->connection->rollback();
  }

  public static function commit()
  {
    DB::instance()->connection->commit();
  }

  public static function get_profiles()
  {
    return DB::instance()->connection->get_profiles();
  }

  private static function add_error( $error )
  {
    DB::instance()->connection->add_error( $error );
  }

  public static function get_errors()
  {
    return DB::instance()->connection->get_errors();
  }

  public static function has_errors()
  {
    return DB::instance()->connection->has_errors();
  }

  public static function clear_errors()
  {
    DB::instance()->connection->clear_errors();
  }

  public static function get_last_error()
  {
    return DB::instance()->connection->get_last_error();
  }

  public static function get_results( $query, $args = array(), $class_name = '\Habari\QueryRecord' )
  {
    return DB::instance()->connection->get_results( $query, $args, $class_name );
  }

  public static function get_row( $query, $args = array(), $class_name = '\Habari\QueryRecord' )
  {
    return DB::instance()->connection->get_row( $query, $args, $class_name );
  }

  public static function get_column( $query, $args = array() )
  {
    return DB::instance()->connection->get_column( $query, $args );
  }

  public static function get_value( $query, $args = array() )
  {
    return DB::instance()->connection->get_value( $query, $args );
  }

  public static function get_keyvalue( $query, $args = array() )
  {
    return DB::instance()->connection->get_keyvalue( $query, $args );
  }

  public static function insert( $table, $fieldvalues )
  {
    return DB::instance()->connection->insert( $table, $fieldvalues );
  }

  public static function exists( $table, $keyfieldvalues )
  {
    return DB::instance()->connection->exists( $table, $keyfieldvalues );
  }

  public static function update( $table, $fieldvalues, $keyfields )
  {
    return DB::instance()->connection->update( $table, $fieldvalues, $keyfields );
  }

  public static function delete( $table, $keyfields )
  {
    return DB::instance()->connection->delete( $table, $keyfields );
  }

  public static function last_insert_id()
  {
    return DB::instance()->connection->last_insert_id( func_num_args() == 1 ? func_get_arg( 0 ) : '' );
  }

  public static function row_count()
  {
    return DB::instance()->connection->row_count();
  }

  public static function dbdelta( $queries, $execute = true, $silent = true, $doinserts = false )
  {
    return DB::instance()->connection->dbdelta( $queries, $execute, $silent, $doinserts );
  }

  public static function upgrade( $old_version )
  {
    return DB::instance()->connection->upgrade( $old_version );
  }

  public static function upgrade_pre( $old_version )
  {
    return DB::instance()->connection->upgrade_pre( $old_version );
  }

  public static function upgrade_post( $old_version )
  {
    return DB::instance()->connection->upgrade_post( $old_version );
  }

  public static function get_driver_name()
  {
    return DB::instance()->connection->get_driver_name();
  }

  public static function get_driver_version()
  {
    return DB::instance()->connection->get_driver_version();
  }

  public static function list_tables()
  {
    return DB::instance()->connection->list_tables();
  }

  public static function is_connected()
  {
    return (DB::instance()->connection instanceof DatabaseConnection && DB::instance()->connection->is_connected());
  }

  public static function in_transaction()
  {
    return DB::instance()->connection->in_transaction();
  }

  public static function quote( $string )
  {
    return DB::instance()->connection->quote( $string );
  }
}

?>