File Source for DBConnectionStack.class.php

<?php
/**
* Zikula Application Framework
*
* @copyright Robert Gasch
* @link http://www.zikula.org
* @version $Id: DBConnectionStack.class.php 24342 2008-06-06 12:03:14Z markwest $
* @license GNU/GPL - http://www.gnu.org/copyleft/gpl.html
* @author Robert Gasch rgasch@gmail.com
* @uses stacked connection handler
* @package Zikula_Core
*/
/**
* This class maintains a stack of database connections. Getting a connection
* will always return the connection object which is currently on top of the
* connections stack (ie: the latest added connection).
*
* @package Zikula_Core
* @subpackage DBConnectionStack
*/
class DBConnectionStack
{
/**
* Initialize a DBConnection and place it on the connection stack
*
* @param name The database alias name in the DBInfo configuration array (optional) (default=null which then defaults to 'default')
*
* @return string The file name which was loaded
*/
function init ($name=null)
{
if (!$name) {
$name = 'default';
}
if (!isset($GLOBALS['PNConfig']['DBInfo'][$name]) ||
!is_array($GLOBALS['PNConfig']['DBInfo'][$name])) {
return pn_exit ("Invalid connection key [$name] ...");
}
$count = (isset($GLOBALS['PNRuntime']['DB']) ? count($GLOBALS['PNRuntime']['DB']) : 0);
if (!defined('_PNINSTALLVER') && $count && $name == $GLOBALS['PNRuntime']['DB'][$count-1]['name']) {
return pn_exit ("Attempting to init database [$name] which is the active database already ...");
}
// Get database parameters
$dbtype = $GLOBALS['PNConfig']['DBInfo'][$name]['dbtype'];
$dbhost = $GLOBALS['PNConfig']['DBInfo'][$name]['dbhost'];
$dbname = $GLOBALS['PNConfig']['DBInfo'][$name]['dbname'];
$dbuname = $GLOBALS['PNConfig']['DBInfo'][$name]['dbuname'];
$dbpass = $GLOBALS['PNConfig']['DBInfo'][$name]['dbpass'];
$pconnect = $GLOBALS['PNConfig']['DBInfo'][$name]['pconnect'];
$dbcharset= $GLOBALS['PNConfig']['DBInfo'][$name]['dbcharset'];
// Start connection
// itevo: /Go; it's more safe to use NConnect instead of Connect because of the following:
// If you create two connections, but both use the same userid and password, PHP will share the
// same connection. This can cause problems if the connections are meant to different databases.
// The solution is to always use different userid's for different databases, or use NConnect().
// NConnect: Always force a new connection. In contrast, PHP sometimes reuses connections when
// you use Connect() or PConnect(). Currently works only on mysql (PHP 4.3.0 or later), postgresql
// and oci8-derived drivers. For other drivers, NConnect() works like Connect().
// If installer, suppress errors because of installer issues when anon db user isnt available - drak
$conn = ADONewConnection($dbtype);
// debug setting for adodb sql
if (isset($GLOBALS['PNConfig']['Debug']['sql_adodb']) && $GLOBALS['PNConfig']['Debug']['sql_adodb']) {
$conn->debug = (int)$GLOBALS['PNConfig']['Debug']['sql_adodb'];
}
$func = ($pconnect ? 'PConnect' : 'NConnect');
if (defined('_PNINSTALLVER')) {
$dbh = @$conn->$func ($dbhost, $dbuname, $dbpass, $dbname);
} else {
$dbh = $conn->$func ($dbhost, $dbuname, $dbpass, $dbname);
}
if (!$dbh) {
return false;
}
global $ADODB_FETCH_MODE;
$ADODB_FETCH_MODE = ADODB_FETCH_NUM;
// force oracle to a consistent date format for comparison methods later on
$dbdriver = _adodb_getdriver($conn->dataProvider, $conn->databaseType, true);
if ($dbdriver=='oci8' || $dbdriver=='oracle') {
$res = $conn->Execute("ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS'");
$res = $conn->Execute("ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS'");
}
// PN .8: set db to utf8 if defined in config.php and the db is in utf8 - for future versions we need to check for inconsistent charsets (BP)
if ($dbdriver=='mysql' || $dbdriver=='mysqli') {
if (isset($dbcharset)) {
$dbcharset = strtolower($dbcharset);
$curdbcharset = $conn->Execute("SHOW VARIABLES LIKE 'character_set_database'");
if ($dbcharset == 'utf8' && $curdbcharset->fields[1] == 'utf8') {
$conn->Execute('set names utf8');
}
}
}
$GLOBALS['PNRuntime']['DB'][$count] = $GLOBALS['PNConfig']['DBInfo'][$name];
$GLOBALS['PNRuntime']['DB'][$count]['alias'] = $name;
$GLOBALS['PNRuntime']['DB'][$count]['dbconn'] = $conn;
$GLOBALS['PNRuntime']['DB'][$count]['dbdriver'] = $dbdriver;
// add the table prefix as this makes integrating other applications easier
$GLOBALS['PNRuntime']['DB'][$count]['prefix'] = $GLOBALS['PNConfig']['System']['prefix'].'_';
return $conn;
}
/**
* Get the DB connection info structure for a connection as defined in config.php.
* If $field is supplied, the value of the specified field is retuerned, otherwise
* the entire connection info array is returned.
*
* @param name the name of the connection info to get. Passing null returns the current (ie: top) connection (optional) (default=null)
* @param field the field of the connection info record to return
*
* @return string The connection info array or the specified field value
*/
function getConnectionInfo ($name=null, $field=null)
{
$count = (isset($GLOBALS['PNRuntime']['DB']) ? count($GLOBALS['PNRuntime']['DB']) : 0);
if (!$count) {
return pn_exit ('Attempted to get info from empty connection stack ...');
}
if (!$name) {
$name = $GLOBALS['PNRuntime']['DB'][$count-1]['alias'];
}
if (!isset($GLOBALS['PNConfig']['DBInfo'][$name]) ||
!is_array($GLOBALS['PNConfig']['DBInfo'][$name])) {
return pn_exit ("Invalid connection key [$name] ...");
}
if ($field) {
if (isset($GLOBALS['PNRuntime']['DB'][$count-1][$field])) {
return $GLOBALS['PNRuntime']['DB'][$count-1][$field];
} else {
return pn_exit("DBConnectionClass::getConnectionInfo: unknown field [$field] requested");
}
}
return $GLOBALS['PNRuntime']['DB'][$count-1];
}
/**
* Get the alias name name of the currently active connection
*
* @return string the name of the currently active connection
*/
function getConnectionName ()
{
return DBConnectionStack::getConnectionInfo (null, 'alias');
}
/**
* Get the DB Alias name of the currently active connection
*
* @return string the dbname of the currently active connection
*/
function getConnectionDBName ()
{
return DBConnectionStack::getConnectionInfo (null, 'dbname');
}
/**
* Get the DB Host of the currently active connection
*
* @return string the host of the currently active connection
*/
function getConnectionDBHost ()
{
return DBConnectionStack::getConnectionInfo (null, 'dbhost');
}
/**
* Get the DB Type of the currently active connection
*
* @return string the type of the currently active connection
*/
function getConnectionDBType ()
{
return DBConnectionStack::getConnectionInfo (null, 'dbtype');
}
/**
* Get the DB driver of the currently active connection. This is not necessarily the same as the DB Type and
* should be used to distinguish between different database types in ADODB
* e.g. both oracle and oci8 use the oci8 driver to load the correct data dictionary include file
*
* @return string the driver of the currently active connection
*/
function getConnectionDBDriver ()
{
$dbdriver = 'undefined';
if (defined('_PNINSTALLVER')) {
// we are installing PN right now so we might not have valid db connection yet
$conn = pnDBGetConn(true);
// hello database?
if ($conn !== false && is_object($conn)) {
$dbdriver = _adodb_getdriver($conn->dataProvider, $conn->databaseType, true);
}
} else {
$dbdriver = DBConnectionStack::getConnectionInfo (null, 'dbdriver');
}
return $dbdriver;
}
/**
* Check whether the current connection is the default one
*
* @return boolean whether or not the current connection is the default one
*/
function isDefaultConnection ()
{
$name = DBConnectionStack::getConnectionName ();
return (strcmp ($name, 'default')==0);
}
/**
* Get the currently active connection (the connection on top of the connection stack)
*
* @param fetchmod The fetchmode to set for the connection
*
* @return the connection object
*/
function getConnection ($fetchmode=ADODB_FETCH_NUM)
{
if (!isset($GLOBALS['PNRuntime']['DB']) && defined('_PNINSTALLVER')) {
return;
}
$count = count($GLOBALS['PNRuntime']['DB']);
if (!$count) {
if (defined('_PNINSTALLVER')) {
return;
} else {
return pn_exit ('Attempted to get connection from empty connection stack ...');
}
}
$conn = $GLOBALS['PNRuntime']['DB'][$count-1]['dbconn'];
switch($fetchmode)
{
case ADODB_FETCH_NUM :
$dbdriver = _adodb_getdriver($conn->dataProvider, $conn->databaseType, true);
if ($dbdriver=='postgres') {
// RNG: workwound for installer errors / adodb V4.94 pgsql driver bug: see http://phplens.com/lens/lensforum/msgs.php?id=15248&x=1
$conn->SetFetchMode(ADODB_FETCH_BOTH);
} else {
$conn->SetFetchMode(ADODB_FETCH_NUM);
}
break;
case ADODB_FETCH_ASSOC :
$conn->SetFetchMode(ADODB_FETCH_ASSOC);
break;
case ADODB_FETCH_DEFAULT :
$conn->SetFetchMode(ADODB_FETCH_DEFAULT);
break;
case ADODB_FETCH_BOTH:
$conn->SetFetchMode(ADODB_FETCH_BOTH);
break;
}
return $conn;
}
/**
* Push a new database connection onto the connection stack
*
* @param name The database alias name in the DBInfo configuration array
*
* @return The database connection
*/
function pushConnection ($name)
{
if (DBConnectionStack::init ($name)) {
return DBConnectionStack::getConnection ();
}
return false;
}
/**
* Pop the currently active connection off the stack.
*
* @param close Whether or not to close the connection (optional) (default=false)
*
* @return boolean The newly active connection
*/
function popConnection ($close=false)
{
$count = count($GLOBALS['PNRuntime']['DB']);
if (!$count){
return pn_exit ('Attempted to pop connection from empty connection stack ...');
}
if ($close) {
$conn = DBConnectionStack::getConnection ();
$conn->Close();
}
unset ($GLOBALS['PNRuntime']['DB'][$count-1]);
return DBConnectionStack::getConnection ();
}
}

Source for file DBConnectionStack.class.php