feature:65 Add support for PHP mysqli extension, activated by default, remove returns of link_identifier

git-svn-id: http://piwigo.org/svn/trunk@20462 68402e56-0260-453c-a942-63ccdbb3a9ee

7 files changed, 861 insertions, 20 deletions

diff --git a/admin/include/c13y_internal.class.php b/admin/include/c13y_internal.class.php
index 313989bfa..27df84246 100644
--- a/admin/include/c13y_internal.class.php
+++ b/admin/include/c13y_internal.class.php
@@ -42,13 +42,17 @@ class c13y_internal
 
     $check_list = array();
 
-    $check_list[] = array('type' => 'PHP', 'current' => phpversion(), 'required' => REQUIRED_PHP_VERSION);
+    $check_list[] = array(
+        'type' => 'PHP',
+        'current' => phpversion(),
+        'required' => REQUIRED_PHP_VERSION,
+        );
 
-    $db_version = pwg_get_db_version();
-    $check_list[] = array('type' => $conf['dblayer'],
-			  'current' => $db_version, 
-			  'required' => constant('REQUIRED_'.str_replace('-', '_', strtoupper($conf['dblayer'])).'_VERSION')
-			  );
+    $check_list[] = array(
+        'type' => 'MySQL',
+        'current' => pwg_get_db_version(), 
+        'required' => REQUIRED_MYSQL_VERSION,
+        );
 
     foreach ($check_list as $elem)
     {
diff --git a/admin/intro.php b/admin/intro.php
index d49f6d48a..c454e50b4 100644
--- a/admin/intro.php
+++ b/admin/intro.php
@@ -197,7 +197,7 @@ $template->assign(
     'PWG_VERSION' => PHPWG_VERSION,
     'OS' => PHP_OS,
     'PHP_VERSION' => phpversion(),
-    'DB_ENGINE' => $conf['dblayer'],
+    'DB_ENGINE' => 'MySQL',
     'DB_VERSION' => $db_version,
     'DB_ELEMENTS' => l10n_dec('%d photo', '%d photos', $nb_elements),
     'DB_CATEGORIES' =>
diff --git a/i.php b/i.php
index c4702c0d7..d0d70cc84 100644
--- a/i.php
+++ b/i.php
@@ -402,8 +402,8 @@ include_once( PHPWG_ROOT_PATH .'/include/derivative_std_params.inc.php');
 
 try
 {
-  $pwg_db_link = pwg_db_connect($conf['db_host'], $conf['db_user'],
-                                $conf['db_password'], $conf['db_base']);
+  pwg_db_connect($conf['db_host'], $conf['db_user'],
+                 $conf['db_password'], $conf['db_base']);
 }
 catch (Exception $e)
 {
@@ -511,7 +511,7 @@ else
 {
   $page['rotation_angle'] = 0;
 }
-pwg_db_close($pwg_db_link);
+pwg_db_close();
 
 if (!try_switch_source($params, $src_mtime) && $params->type==IMG_CUSTOM)
 {
diff --git a/include/dblayer/functions_mysql.inc.php b/include/dblayer/functions_mysql.inc.php
index 0b2c35195..f8182bdf4 100644
--- a/include/dblayer/functions_mysql.inc.php
+++ b/include/dblayer/functions_mysql.inc.php
@@ -40,11 +40,7 @@ function pwg_db_connect($host, $user, $password, $database)
   {
     throw new Exception("Can't connect to server");
   }
-  if (mysql_select_db($database, $link))
-  {
-    return $link;
-  }
-  else
+  if (!mysql_select_db($database, $link))
   {
     throw new Exception('Connection to server succeed, but it was impossible to connect to database');
   }
@@ -138,7 +134,7 @@ SELECT IF(MAX('.$column.')+1 IS NULL, 1, MAX('.$column.')+1)
   return $next;
 }
 
-function pwg_db_changes($result) 
+function pwg_db_changes() 
 {
   return mysql_affected_rows();
 }
@@ -173,14 +169,14 @@ function pwg_db_real_escape_string($s)
   return mysql_real_escape_string($s);
 }
 
-function pwg_db_insert_id($table=null, $column='id')
+function pwg_db_insert_id()
 {
   return mysql_insert_id();
 }
 
-function pwg_db_close($link=null)
+function pwg_db_close()
 {
-  return mysql_close($link);
+  return mysql_close();
 }
 
 /**
diff --git a/include/dblayer/functions_mysqli.inc.php b/include/dblayer/functions_mysqli.inc.php
new file mode 100644
index 000000000..af42b865b
--- /dev/null
+++ b/include/dblayer/functions_mysqli.inc.php
@@ -0,0 +1,798 @@
+<?php
+// +-----------------------------------------------------------------------+
+// | Piwigo - a PHP based photo gallery                                    |
+// +-----------------------------------------------------------------------+
+// | Copyright(C) 2008-2012 Piwigo Team                  http://piwigo.org |
+// | Copyright(C) 2003-2008 PhpWebGallery Team    http://phpwebgallery.net |
+// | Copyright(C) 2002-2003 Pierrick LE GALL   http://le-gall.net/pierrick |
+// +-----------------------------------------------------------------------+
+// | This program is free software; you can redistribute it and/or modify  |
+// | it under the terms of the GNU General Public License as published by  |
+// | the Free Software Foundation                                          |
+// |                                                                       |
+// | This program is distributed in the hope that it will be useful, but   |
+// | WITHOUT ANY WARRANTY; without even the implied warranty of            |
+// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      |
+// | General Public License for more details.                              |
+// |                                                                       |
+// | You should have received a copy of the GNU General Public License     |
+// | along with this program; if not, write to the Free Software           |
+// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
+// | USA.                                                                  |
+// +-----------------------------------------------------------------------+
+
+define('DB_ENGINE', 'MySQL');
+define('REQUIRED_MYSQL_VERSION', '5.0.0');
+
+define('DB_REGEX_OPERATOR', 'REGEXP');
+define('DB_RANDOM_FUNCTION', 'RAND');
+
+/**
+ *
+ * simple functions
+ *
+ */
+
+function pwg_db_connect($host, $user, $password, $database)
+{
+  global $mysqli;
+  
+  $mysqli = new mysqli($host, $user, $password);
+  if (mysqli_connect_error())
+  {
+    throw new Exception("Can't connect to server");
+  }
+  if (!$mysqli->select_db($database))
+  {
+    throw new Exception('Connection to server succeed, but it was impossible to connect to database');
+  }
+}
+
+function pwg_db_check_charset() 
+{
+  $db_charset = 'utf8';
+  if (defined('DB_CHARSET') and DB_CHARSET != '')
+  {
+    $db_charset = DB_CHARSET;
+  }
+  pwg_query('SET NAMES "'.$db_charset.'"');
+}
+
+function pwg_db_check_version()
+{
+  $current_mysql = pwg_get_db_version();
+  if (version_compare($current_mysql, REQUIRED_MYSQL_VERSION, '<'))
+  {
+    fatal_error(
+      sprintf(
+        'your MySQL version is too old, you have "%s" and you need at least "%s"',
+        $current_mysql,
+        REQUIRED_MYSQL_VERSION
+        )
+      );
+  }
+}
+
+function pwg_get_db_version() 
+{
+  global $mysqli;
+  
+  return $mysqli->server_info;
+}
+
+function pwg_query($query)
+{
+  global $mysqli, $conf, $page, $debug, $t2;
+
+  $start = microtime(true);
+  ($result = $mysqli->query($query)) or my_error($query, $conf['die_on_sql_error']);
+
+  $time = microtime(true) - $start;
+
+  if (!isset($page['count_queries']))
+  {
+    $page['count_queries'] = 0;
+    $page['queries_time'] = 0;
+  }
+
+  $page['count_queries']++;
+  $page['queries_time']+= $time;
+
+  if ($conf['show_queries'])
+  {
+    $output = '';
+    $output.= '<pre>['.$page['count_queries'].'] ';
+    $output.= "\n".$query;
+    $output.= "\n".'(this query time : ';
+    $output.= '<b>'.number_format($time, 3, '.', ' ').' s)</b>';
+    $output.= "\n".'(total SQL time  : ';
+    $output.= number_format($page['queries_time'], 3, '.', ' ').' s)';
+    $output.= "\n".'(total time      : ';
+    $output.= number_format( ($time+$start-$t2), 3, '.', ' ').' s)';
+    if ( $result!=null and preg_match('/\s*SELECT\s+/i',$query) )
+    {
+      $output.= "\n".'(num rows        : ';
+      $output.= pwg_db_num_rows($result).' )';
+    }
+    elseif ( $result!=null
+      and preg_match('/\s*INSERT|UPDATE|REPLACE|DELETE\s+/i',$query) )
+    {
+      $output.= "\n".'(affected rows   : ';
+      $output.= pwg_db_changes().' )';
+    }
+    $output.= "</pre>\n";
+
+    $debug .= $output;
+  }
+
+  return $result;
+}
+
+function pwg_db_nextval($column, $table)
+{
+  $query = '
+SELECT IF(MAX('.$column.')+1 IS NULL, 1, MAX('.$column.')+1)
+  FROM '.$table;
+  list($next) = pwg_db_fetch_row(pwg_query($query));
+
+  return $next;
+}
+
+function pwg_db_changes() 
+{
+  global $mysqli;
+  
+  return $mysqli->affected_rows;
+}
+
+function pwg_db_num_rows($result) 
+{
+  return $result->num_rows;
+}
+
+function pwg_db_fetch_assoc($result)
+{
+  return $result->fetch_assoc();
+}
+
+function pwg_db_fetch_row($result)
+{
+  return $result->fetch_row();
+}
+
+function pwg_db_fetch_object($result)
+{
+  return $result->fetch_object();
+}
+
+function pwg_db_free_result($result) 
+{
+  return $result->free_result();
+}
+
+function pwg_db_real_escape_string($s)
+{
+  global $mysqli;
+  
+  return $mysqli->real_escape_string($s);
+}
+
+function pwg_db_insert_id()
+{
+  global $mysqli;
+  
+  return $mysqli->insert_id;
+}
+
+function pwg_db_close()
+{
+  global $mysqli;
+  
+  return $mysqli->close();
+}
+
+/**
+ *
+ * complex functions
+ *
+ */
+
+/**
+ * creates an array based on a query, this function is a very common pattern
+ * used here
+ *
+ * @param string $query
+ * @param string $fieldname optional
+ * @return array
+ */
+function array_from_query($query, $fieldname=false)
+{
+  $array = array();
+
+  $result = pwg_query($query);
+  if (false === $fieldname)
+  {
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      $array[] = $row;      
+    }
+  }
+  else
+  {
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      $array[] = $row[$fieldname];
+    }
+  }
+  return $array;
+}
+
+define('MASS_UPDATES_SKIP_EMPTY', 1);
+/**
+ * updates multiple lines in a table
+ *
+ * @param string table_name
+ * @param array dbfields
+ * @param array datas
+ * @param int flags - if MASS_UPDATES_SKIP_EMPTY - empty values do not overwrite existing ones
+ * @return void
+ */
+function mass_updates($tablename, $dbfields, $datas, $flags=0)
+{
+  if (count($datas) == 0)
+    return;
+  
+  // depending on the MySQL version, we use the multi table update or N update queries
+  if (count($datas) < 10)
+  {
+    foreach ($datas as $data)
+    {
+      $query = '
+UPDATE '.$tablename.'
+  SET ';
+      $is_first = true;
+      foreach ($dbfields['update'] as $key)
+      {
+        $separator = $is_first ? '' : ",\n    ";
+
+        if (isset($data[$key]) and $data[$key] != '')
+        {
+          $query.= $separator.$key.' = \''.$data[$key].'\'';
+        }
+        else
+        {
+          if ( $flags & MASS_UPDATES_SKIP_EMPTY )
+            continue; // next field
+          $query.= "$separator$key = NULL";
+        }
+        $is_first = false;
+      }
+      if (!$is_first)
+      {// only if one field at least updated
+        $query.= '
+  WHERE ';
+        $is_first = true;
+        foreach ($dbfields['primary'] as $key)
+        {
+          if (!$is_first)
+          {
+            $query.= ' AND ';
+          }
+          if ( isset($data[$key]) )
+          {
+            $query.= $key.' = \''.$data[$key].'\'';
+          }
+          else
+          {
+            $query.= $key.' IS NULL';
+          }
+          $is_first = false;
+        }
+        pwg_query($query);
+      }
+    } // foreach update
+  } // if mysqli_ver or count<X
+  else
+  {
+    // creation of the temporary table
+    $query = '
+SHOW FULL COLUMNS FROM '.$tablename;
+    $result = pwg_query($query);
+    $columns = array();
+    $all_fields = array_merge($dbfields['primary'], $dbfields['update']);
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      if (in_array($row['Field'], $all_fields))
+      {
+        $column = $row['Field'];
+        $column.= ' '.$row['Type'];
+
+        $nullable = true;
+        if (!isset($row['Null']) or $row['Null'] == '' or $row['Null']=='NO')
+        {
+          $column.= ' NOT NULL';
+          $nullable = false;
+        }
+        if (isset($row['Default']))
+        {
+          $column.= " default '".$row['Default']."'";
+        }
+        elseif ($nullable)
+        {
+          $column.= " default NULL";
+        }
+        if (isset($row['Collation']) and $row['Collation'] != 'NULL')
+        {
+          $column.= " collate '".$row['Collation']."'";
+        }
+        array_push($columns, $column);
+      }
+    }
+
+    $temporary_tablename = $tablename.'_'.micro_seconds();
+
+    $query = '
+CREATE TABLE '.$temporary_tablename.'
+(
+  '.implode(",\n  ", $columns).',
+  UNIQUE KEY the_key ('.implode(',', $dbfields['primary']).')
+)';
+
+    pwg_query($query);
+    mass_inserts($temporary_tablename, $all_fields, $datas);
+    if ( $flags & MASS_UPDATES_SKIP_EMPTY )
+      $func_set = create_function('$s', 'return "t1.$s = IFNULL(t2.$s, t1.$s)";');
+    else
+      $func_set = create_function('$s', 'return "t1.$s = t2.$s";');
+
+    // update of images table by joining with temporary table
+    $query = '
+UPDATE '.$tablename.' AS t1, '.$temporary_tablename.' AS t2
+  SET '.
+      implode(
+        "\n    , ",
+        array_map($func_set,$dbfields['update'])
+        ).'
+  WHERE '.
+      implode(
+        "\n    AND ",
+        array_map(
+          create_function('$s', 'return "t1.$s = t2.$s";'),
+          $dbfields['primary']
+          )
+        );
+    pwg_query($query);
+    $query = '
+DROP TABLE '.$temporary_tablename;
+    pwg_query($query);
+  }
+}
+
+/**
+ * updates one line in a table
+ *
+ * @param string table_name
+ * @param array set_fields
+ * @param array where_fields
+ * @param int flags - if MASS_UPDATES_SKIP_EMPTY - empty values do not overwrite existing ones
+ * @return void
+ */
+function single_update($tablename, $set_fields, $where_fields, $flags=0)
+{
+  if (count($set_fields) == 0)
+  {
+    return;
+  }
+
+  $query = '
+UPDATE '.$tablename.'
+  SET ';
+  $is_first = true;
+  foreach ($set_fields as $key => $value)
+  {
+    $separator = $is_first ? '' : ",\n    ";
+
+    if (isset($value) and $value !== '')
+    {
+      $query.= $separator.$key.' = \''.$value.'\'';
+    }
+    else
+    {
+      if ( $flags & MASS_UPDATES_SKIP_EMPTY )
+        continue; // next field
+      $query.= "$separator$key = NULL";
+    }
+    $is_first = false;
+  }
+  if (!$is_first)
+  {// only if one field at least updated
+    $query.= '
+  WHERE ';
+    $is_first = true;
+    foreach ($where_fields as $key => $value)
+    {
+      if (!$is_first)
+      {
+        $query.= ' AND ';
+      }
+      if ( isset($value) )
+      {
+        $query.= $key.' = \''.$value.'\'';
+      }
+      else
+      {
+        $query.= $key.' IS NULL';
+      }
+      $is_first = false;
+    }
+    pwg_query($query);
+  }
+}
+
+
+/**
+ * inserts multiple lines in a table
+ *
+ * @param string table_name
+ * @param array dbfields
+ * @param array inserts
+ * @return void
+ */
+function mass_inserts($table_name, $dbfields, $datas, $options=array())
+{
+  $ignore = '';
+  if (isset($options['ignore']) and $options['ignore'])
+  {
+    $ignore = 'IGNORE';
+  }
+  
+  if (count($datas) != 0)
+  {
+    $first = true;
+
+    $query = 'SHOW VARIABLES LIKE \'max_allowed_packet\'';
+    list(, $packet_size) = pwg_db_fetch_row(pwg_query($query));
+    $packet_size = $packet_size - 2000; // The last list of values MUST not exceed 2000 character*/
+    $query = '';
+
+    foreach ($datas as $insert)
+    {
+      if (strlen($query) >= $packet_size)
+      {
+        pwg_query($query);
+        $first = true;
+      }
+
+      if ($first)
+      {
+        $query = '
+INSERT '.$ignore.' INTO '.$table_name.'
+  ('.implode(',', $dbfields).')
+  VALUES';
+        $first = false;
+      }
+      else
+      {
+        $query .= '
+  , ';
+      }
+
+      $query .= '(';
+      foreach ($dbfields as $field_id => $dbfield)
+      {
+        if ($field_id > 0)
+        {
+          $query .= ',';
+        }
+
+        if (!isset($insert[$dbfield]) or $insert[$dbfield] === '')
+        {
+          $query .= 'NULL';
+        }
+        else
+        {
+          $query .= "'".$insert[$dbfield]."'";
+        }
+      }
+      $query .= ')';
+    }
+    pwg_query($query);
+  }
+}
+
+/**
+ * inserts one line in a table
+ *
+ * @param string table_name
+ * @param array dbfields
+ * @param array insert
+ * @return void
+ */
+function single_insert($table_name, $data)
+{
+  if (count($data) != 0)
+  {
+    $query = '
+INSERT INTO '.$table_name.'
+  ('.implode(',', array_keys($data)).')
+  VALUES';
+
+    $query .= '(';
+    $is_first = true;
+    foreach ($data as $key => $value)
+    {
+      if (!$is_first)
+      {
+        $query .= ',';
+      }
+      else
+      {
+        $is_first = false;
+      }
+      
+      if ($value === '')
+      {
+        $query .= 'NULL';
+      }
+      else
+      {
+        $query .= "'".$value."'";
+      }
+    }
+    $query .= ')';
+    
+    pwg_query($query);
+  }
+}
+
+/**
+ * Do maintenance on all PWG tables
+ *
+ * @return none
+ */
+function do_maintenance_all_tables()
+{
+  global $prefixeTable, $page;
+
+  $all_tables = array();
+
+  // List all tables
+  $query = 'SHOW TABLES LIKE \''.$prefixeTable.'%\'';
+  $result = pwg_query($query);
+  while ($row = pwg_db_fetch_row($result))
+  {
+    array_push($all_tables, $row[0]);
+  }
+
+  // Repair all tables
+  $query = 'REPAIR TABLE '.implode(', ', $all_tables);
+  $mysqli_rc = pwg_query($query);
+
+  // Re-Order all tables
+  foreach ($all_tables as $table_name)
+  {
+    $all_primary_key = array();
+
+    $query = 'DESC '.$table_name.';';
+    $result = pwg_query($query);
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      if ($row['Key'] == 'PRI')
+      {
+        array_push($all_primary_key, $row['Field']);
+      }
+    }
+
+    if (count($all_primary_key) != 0)
+    {
+      $query = 'ALTER TABLE '.$table_name.' ORDER BY '.implode(', ', $all_primary_key).';';
+      $mysqli_rc = $mysqli_rc && pwg_query($query);
+    }
+  }
+
+  // Optimize all tables
+  $query = 'OPTIMIZE TABLE '.implode(', ', $all_tables);
+  $mysqli_rc = $mysqli_rc && pwg_query($query);
+  if ($mysqli_rc)
+  {
+    array_push(
+          $page['infos'],
+          l10n('All optimizations have been successfully completed.')
+          );
+  }
+  else
+  {
+    array_push(
+          $page['errors'],
+          l10n('Optimizations have been completed with some errors.')
+          );
+  }
+}
+
+function pwg_db_concat($array)
+{
+  $string = implode($array, ',');
+  return 'CONCAT('. $string.')';
+}
+
+function pwg_db_concat_ws($array, $separator)
+{
+  $string = implode($array, ',');
+  return 'CONCAT_WS(\''.$separator.'\','. $string.')';
+}
+
+function pwg_db_cast_to_text($string)
+{
+  return $string;
+}
+
+/**
+ * returns an array containing the possible values of an enum field
+ *
+ * @param string tablename
+ * @param string fieldname
+ */
+function get_enums($table, $field)
+{
+  // retrieving the properties of the table. Each line represents a field :
+  // columns are 'Field', 'Type'
+  $result = pwg_query('desc '.$table);
+  while ($row = pwg_db_fetch_assoc($result))
+  {
+    // we are only interested in the the field given in parameter for the
+    // function
+    if ($row['Field'] == $field)
+    {
+      // retrieving possible values of the enum field
+      // enum('blue','green','black')
+      $options = explode(',', substr($row['Type'], 5, -1));
+      foreach ($options as $i => $option)
+      {
+        $options[$i] = str_replace("'", '',$option);
+      }
+    }
+  }
+  pwg_db_free_result($result);
+  return $options;
+}
+
+/**
+ * Smartly checks if a variable is equivalent to true or false
+ *
+ * @param mixed input
+ * @return bool
+ */
+function get_boolean($input)
+{
+  if ('false' === strtolower($input))
+  {
+    return false;
+  }
+
+  return (bool)$input;
+}
+
+/**
+ * returns boolean string 'true' or 'false' if the given var is boolean
+ *
+ * @param mixed $var
+ * @return mixed
+ */
+function boolean_to_string($var)
+{
+  if (is_bool($var))
+  {
+    return $var ? 'true' : 'false';
+  }
+  else
+  {
+    return $var;
+  }
+}
+
+/**
+ *
+ * interval and date functions 
+ *
+ */
+
+function pwg_db_get_recent_period_expression($period, $date='CURRENT_DATE')
+{
+  if ($date!='CURRENT_DATE')
+  {
+    $date = '\''.$date.'\'';
+  }
+
+  return 'SUBDATE('.$date.',INTERVAL '.$period.' DAY)';
+}
+
+function pwg_db_get_recent_period($period, $date='CURRENT_DATE')
+{
+  $query = '
+SELECT '.pwg_db_get_recent_period_expression($period);
+  list($d) = pwg_db_fetch_row(pwg_query($query));
+
+  return $d;
+}
+
+function pwg_db_get_flood_period_expression($seconds)
+{
+  return 'SUBDATE(now(), INTERVAL '.$seconds.' SECOND)';
+}
+
+function pwg_db_get_hour($date) 
+{
+  return 'hour('.$date.')';
+}
+
+function pwg_db_get_date_YYYYMM($date)
+{
+  return 'DATE_FORMAT('.$date.', \'%Y%m\')';
+}
+
+function pwg_db_get_date_MMDD($date)
+{
+  return 'DATE_FORMAT('.$date.', \'%m%d\')';
+}
+
+function pwg_db_get_year($date)
+{
+  return 'YEAR('.$date.')';
+}
+
+function pwg_db_get_month($date)
+{
+  return 'MONTH('.$date.')';
+}
+
+function pwg_db_get_week($date, $mode=null)
+{
+  if ($mode)
+  {
+    return 'WEEK('.$date.', '.$mode.')';
+  }
+  else
+  {
+    return 'WEEK('.$date.')';
+  }
+}
+
+function pwg_db_get_dayofmonth($date)
+{
+  return 'DAYOFMONTH('.$date.')';
+}
+
+function pwg_db_get_dayofweek($date)
+{
+  return 'DAYOFWEEK('.$date.')';
+}
+
+function pwg_db_get_weekday($date)
+{
+  return 'WEEKDAY('.$date.')';
+}
+
+function pwg_db_date_to_ts($date) 
+{
+  return 'UNIX_TIMESTAMP('.$date.')';
+}
+
+// my_error returns (or send to standard output) the message concerning the
+// error occured for the last mysql query.
+function my_error($header, $die)
+{
+  global $mysqli;
+  
+  $error = "[mysql error ".$mysqli->errno.'] '.$mysqli->error."\n";
+  $error .= $header;
+
+  if ($die)
+  {
+    fatal_error($error);
+  }
+  echo("<pre>");
+  trigger_error($error, E_USER_WARNING);
+  echo("</pre>");
+}
+
+?>
\ No newline at end of file
diff --git a/install.php b/install.php
index 8d8704087..bc9bc2144 100644
--- a/install.php
+++ b/install.php
@@ -128,7 +128,7 @@ $dbhost = (!empty($_POST['dbhost'])) ? $_POST['dbhost'] : 'localhost';
 $dbuser = (!empty($_POST['dbuser'])) ? $_POST['dbuser'] : '';
 $dbpasswd = (!empty($_POST['dbpasswd'])) ? $_POST['dbpasswd'] : '';
 $dbname = (!empty($_POST['dbname'])) ? $_POST['dbname'] : '';
-$dblayer = 'mysql';
+$dblayer = extension_loaded('mysqli') ? 'mysqli' : 'mysql';
 
 $admin_name = (!empty($_POST['admin_name'])) ? $_POST['admin_name'] : '';
 $admin_pass1 = (!empty($_POST['admin_pass1'])) ? $_POST['admin_pass1'] : '';
diff --git a/install/db/134-database.php b/install/db/134-database.php
new file mode 100644
index 000000000..235a72331
--- /dev/null
+++ b/install/db/134-database.php
@@ -0,0 +1,43 @@
+<?php
+// +-----------------------------------------------------------------------+
+// | Piwigo - a PHP based photo gallery                                    |
+// +-----------------------------------------------------------------------+
+// | Copyright(C) 2008-2013 Piwigo Team                  http://piwigo.org |
+// | Copyright(C) 2003-2008 PhpWebGallery Team    http://phpwebgallery.net |
+// | Copyright(C) 2002-2003 Pierrick LE GALL   http://le-gall.net/pierrick |
+// +-----------------------------------------------------------------------+
+// | This program is free software; you can redistribute it and/or modify  |
+// | it under the terms of the GNU General Public License as published by  |
+// | the Free Software Foundation                                          |
+// |                                                                       |
+// | This program is distributed in the hope that it will be useful, but   |
+// | WITHOUT ANY WARRANTY; without even the implied warranty of            |
+// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      |
+// | General Public License for more details.                              |
+// |                                                                       |
+// | You should have received a copy of the GNU General Public License     |
+// | along with this program; if not, write to the Free Software           |
+// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
+// | USA.                                                                  |
+// +-----------------------------------------------------------------------+
+
+defined('PHPWG_ROOT_PATH') or die('Hacking attempt!');
+
+$upgrade_description = 'replace dblayer to "mysqli" if available.';
+
+global $conf;
+
+$config_file = PHPWG_ROOT_PATH.PWG_LOCAL_DIR .'config/database.inc.php';
+
+if ( extension_loaded('mysqli') and $conf['dblayer']=='mysql' and is_writable($config_file) )
+{
+  $file_content = file_get_contents($config_file);
+  $file_content = preg_replace(
+                            '#\$conf\[\'dblayer\'\]( *)=( *)\'mysql\';#', 
+                            '$conf[\'dblayer\']$1=$2\'mysqli\';', 
+                            $file_content);
+  file_put_contents($config_file, $file_content);
+}
+
+echo "\n".$upgrade_description."\n";
+?>
\ No newline at end of file