mysqli.class.php

<?php
/* Copyright (C) 2001		Fabien Seisen			<seisen@linuxfr.org>
 * Copyright (C) 2002-2005	Rodolphe Quiedeville	<rodolphe@quiedeville.org>
 * Copyright (C) 2004-2011	Laurent Destailleur		<eldy@users.sourceforge.net>
 * Copyright (C) 2006		Andre Cianfarani		<acianfa@free.fr>
 * Copyright (C) 2005-2012	Regis Houssin			<regis.houssin@capnetworks.com>
 *
 * 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; either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

/**
 *	\file       htdocs/core/db/mysqli.class.php
 *	\brief      Class file to manage Dolibarr database access for a Mysql database
 */

require_once DOL_DOCUMENT_ROOT .'/core/db/DoliDB.class.php';

/**
 *	Class to manage Dolibarr database access for a Mysql database
 */
class DoliDBMysqli extends DoliDB
{
    //! Database type
    public $type='mysqli';
    //! Database label
    static $label='MySQL';
    //! Version min database
    static $versionmin=array(4,1,0);
	//! Resultset of last query
	private $_results;

    /**
	 *	Constructor.
	 *	This create an opened connexion to a database server and eventually to a database
	 *
	 *	@param      string	$type		Type of database (mysql, pgsql...)
	 *	@param	    string	$host		Address of database server
	 *	@param	    string	$user		Nom de l'utilisateur autorise
	 *	@param	    string	$pass		Mot de passe
	 *	@param	    string	$name		Nom de la database
	 *	@param	    int		$port		Port of database server
	 *	@return	    int					1 if OK, 0 if not
     */
    function __construct($type, $host, $user, $pass, $name='', $port=0)
    {
        global $conf,$langs;

        // Note that having "static" property for "$forcecharset" and "$forcecollate" will make error here in strict mode, so they are not static
        if (! empty($conf->db->character_set)) $this->forcecharset=$conf->db->character_set;
        if (! empty($conf->db->dolibarr_main_db_collation)) $this->forcecollate=$conf->db->dolibarr_main_db_collation;

        $this->database_user=$user;

        $this->transaction_opened=0;

        //print "Name DB: $host,$user,$pass,$name<br>";

        if (! function_exists("mysqli_connect"))
        {
            $this->connected = 0;
            $this->ok = 0;
            $this->error="Mysqli PHP functions for using Mysqli driver are not available in this version of PHP. Try to use another driver.";
            dol_syslog(get_class($this)."::DoliDBMysqli : Mysqli PHP functions for using Mysqli driver are not available in this version of PHP. Try to use another driver.",LOG_ERR);
            return $this->ok;
        }

        if (! $host)
        {
            $this->connected = 0;
            $this->ok = 0;
            $this->error=$langs->trans("ErrorWrongHostParameter");
            dol_syslog(get_class($this)."::DoliDBMysqli : Erreur Connect, wrong host parameters",LOG_ERR);
            return $this->ok;
        }

        // Essai connexion serveur
        // We do not try to connect to database, only to server. Connect to database is done later in constrcutor
        $this->db = $this->connect($host, $user, $pass, '', $port);

        if ($this->db)
        {
            $this->connected = 1;
            $this->ok = 1;
        }
        else
        {
            // host, login ou password incorrect
            $this->connected = 0;
            $this->ok = 0;
            $this->error=mysqli_connect_error();
            dol_syslog(get_class($this)."::DoliDBMysqli : Erreur Connect mysqli_connect_error=".$this->error,LOG_ERR);
        }

        // Si connexion serveur ok et si connexion base demandee, on essaie connexion base
        if ($this->connected && $name)
        {
            if ($this->select_db($name))
            {
                $this->database_selected = 1;
                $this->database_name = $name;
                $this->ok = 1;

                // If client connected with different charset than Dolibarr HTML output
                $clientmustbe='';
                if (preg_match('/UTF-8/i',$conf->file->character_set_client))      $clientmustbe='utf8';
                if (preg_match('/ISO-8859-1/i',$conf->file->character_set_client)) $clientmustbe='latin1';
                if (mysqli_character_set_name($this->db) != $clientmustbe)
                {
                    $this->query("SET NAMES '".$clientmustbe."'", $this->db);
                    //$this->query("SET CHARACTER SET ". $this->forcecharset);
                }
            }
            else
            {
                $this->database_selected = 0;
                $this->database_name = '';
                $this->ok = 0;
                $this->error=$this->error();
                dol_syslog(get_class($this)."::DoliDBMysqli : Erreur Select_db ".$this->error,LOG_ERR);
            }
        }
        else
        {
            // Pas de selection de base demandee, ok ou ko
            $this->database_selected = 0;

            if ($this->connected)
            {
                // If client connected with different charset than Dolibarr HTML output
                $clientmustbe='';
                if (preg_match('/UTF-8/i',$conf->file->character_set_client))      $clientmustbe='utf8';
                if (preg_match('/ISO-8859-1/i',$conf->file->character_set_client)) $clientmustbe='latin1';
                if (mysqli_character_set_name($this->db) != $clientmustbe)
                {
                    $this->query("SET NAMES '".$clientmustbe."'", $this->db);
                    //$this->query("SET CHARACTER SET ". $this->forcecharset);
                }
            }
        }

        return $this->ok;
    }


    /**
     *  Convert a SQL request in Mysql syntax to native syntax
     *
     *  @param     string	$line   SQL request line to convert
     *  @param     string	$type	Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
     *  @return    string   		SQL request line converted
     */
    static function convertSQLFromMysql($line,$type='ddl')
    {
        return $line;
    }

	/**
	 *	Select a database
	 *
	 *	@param	    string	$database	Name of database
	 *	@return	    boolean  		    true if OK, false if KO
	 */
    function select_db($database)
    {
        dol_syslog(get_class($this)."::select_db database=".$database, LOG_DEBUG);
        return mysqli_select_db($this->db,$database);
    }


    /**
	 *	Connexion to server
	 *
	 *	@param	    string	$host		database server host
	 *	@param	    string	$login		login
	 *	@param	    string	$passwd		password
	 *	@param		string	$name		name of database (not used for mysql, used for pgsql)
	 *	@param		string	$port		Port of database server
	 *	@return		resource			Database access handler
	 *	@see		close
     */
    function connect($host, $login, $passwd, $name, $port=0)
    {
        dol_syslog(get_class($this)."::connect host=$host, port=$port, login=$login, passwd=--hidden--, name=$name",LOG_DEBUG);

        $newhost=$host;
        $newport=$port;

        // With mysqli, port must be in connect parameters
        if (! $newport) $newport=3306;

        $this->db  = @mysqli_connect($newhost, $login, $passwd, $name, $newport);

        //print "Resultat fonction connect: ".$this->db;
        return $this->db;
    }

    /**
	 *	Return version of database server
	 *
	 *	@return	        string      Version string
     */
    function getVersion()
    {
        return mysqli_get_server_info($this->db);
    }

    /**
     *	Return version of database client driver
     *
     *	@return	        string      Version string
     */
    function getDriverInfo()
    {
    	return mysqli_get_client_info($this->db);
    }


    /**
     *  Close database connexion
     *
     *  @return     boolean     True if disconnect successfull, false otherwise
     *  @see        connect
     */
    function close()
    {
        if ($this->db)
        {
	        if ($this->transaction_opened > 0) dol_syslog(get_class($this)."::close Closing a connection with an opened transaction depth=".$this->transaction_opened,LOG_ERR);
            $this->connected=0;
            return mysqli_close($this->db);
        }
        return false;
    }

    /**
     * 	Execute a SQL request and return the resultset
     *
     * 	@param	string	$query			SQL query string
     * 	@param	int		$usesavepoint	0=Default mode, 1=Run a savepoint before and a rollbock to savepoint if error (this allow to have some request with errors inside global transactions).
     * 									Note that with Mysql, this parameter is not used as Myssql can already commit a transaction even if one request is in error, without using savepoints.
     *  @param  string	$type           Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
     *	@return	resource    			Resultset of answer
     */
    function query($query,$usesavepoint=0,$type='auto')
    {
        $query = trim($query);
        if (! $this->database_name)
        {
            // Ordre SQL ne necessitant pas de connexion a une base (exemple: CREATE DATABASE)
            $ret = mysqli_query($this->db,$query);
        }
        else
        {
            $ret = mysqli_query($this->db,$query);
        }

        if (! preg_match("/^COMMIT/i",$query) && ! preg_match("/^ROLLBACK/i",$query))
        {
            // Si requete utilisateur, on la sauvegarde ainsi que son resultset
            if (! $ret)
            {
                $this->lastqueryerror = $query;
                $this->lasterror = $this->error();
                $this->lasterrno = $this->errno();
                dol_syslog(get_class($this)."::query SQL error: ".$query." ".$this->lasterrno." ".$this->lasterror, LOG_WARNING);
            }
            $this->lastquery=$query;
            $this->_results = $ret;
        }

        return $ret;
    }

    /**
     *	Renvoie la ligne courante (comme un objet) pour le curseur resultset
     *
     *	@param	Resultset	$resultset  Curseur de la requete voulue
     *	@return	Object					Object result line or false if KO or end of cursor
     */
    function fetch_object($resultset)
    {
        // Si le resultset n'est pas fourni, on prend le dernier utilise sur cette connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        return mysqli_fetch_object($resultset);
    }


    /**
     *	Return datas as an array
     *
     *	@param	Resultset	$resultset  Resultset of request
     *	@return	array					Array
     */
    function fetch_array($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        return mysqli_fetch_array($resultset);
    }

    /**
     *	Return datas as an array
     *
     *	@param	Resultset	$resultset  Resultset of request
     *	@return	array					Array
     */
    function fetch_row($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_bool($resultset))
        {
            if (! is_object($resultset)) { $resultset=$this->_results; }
            return mysqli_fetch_row($resultset);
        }
        else
        {
            // si le curseur est un booleen on retourne la valeur 0
            return 0;
        }
    }

    /**
     *	Return number of lines for result of a SELECT
     *
     *	@param	Resultset	$resultset  Resulset of requests
     *	@return int		    			Nb of lines
     *	@see    affected_rows
     */
    function num_rows($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        return mysqli_num_rows($resultset);
    }

    /**
     *	Renvoie le nombre de lignes dans le resultat d'une requete INSERT, DELETE ou UPDATE
     *
     *	@param	resultset	$resultset   Curseur de la requete voulue
     *	@return int		    Nombre de lignes
     *	@see    num_rows
     */
    function affected_rows($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        // mysql necessite un link de base pour cette fonction contrairement
        // a pqsql qui prend un resultset
        return mysqli_affected_rows($this->db);
    }


    /**
     *	Libere le dernier resultset utilise sur cette connexion
     *
     *	@param  resultset	$resultset   Curseur de la requete voulue
     *	@return	void
     */
    function free($resultset=0)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        // Si resultset en est un, on libere la memoire
        if (is_object($resultset)) mysqli_free_result($resultset);
    }

    /**
     *	Escape a string to insert data
     *
     *	@param	string	$stringtoencode		String to escape
     *	@return	string						String escaped
     */
    function escape($stringtoencode)
    {
        return addslashes($stringtoencode);
    }

    /**
     *	Return generic error code of last operation.
     *
     *	@return	string		Error code (Exemples: DB_ERROR_TABLE_ALREADY_EXISTS, DB_ERROR_RECORD_ALREADY_EXISTS...)
     */
    function errno()
    {
        if (! $this->connected) {
            // Si il y a eu echec de connexion, $this->db n'est pas valide.
            return 'DB_ERROR_FAILED_TO_CONNECT';
        }
        else {
            // Constants to convert a MySql error code to a generic Dolibarr error code
            $errorcode_map = array(
            1004 => 'DB_ERROR_CANNOT_CREATE',
            1005 => 'DB_ERROR_CANNOT_CREATE',
            1006 => 'DB_ERROR_CANNOT_CREATE',
            1007 => 'DB_ERROR_ALREADY_EXISTS',
            1008 => 'DB_ERROR_CANNOT_DROP',
            1022 => 'DB_ERROR_KEY_NAME_ALREADY_EXISTS',
            1025 => 'DB_ERROR_NO_FOREIGN_KEY_TO_DROP',
            1044 => 'DB_ERROR_ACCESSDENIED',
            1046 => 'DB_ERROR_NODBSELECTED',
            1048 => 'DB_ERROR_CONSTRAINT',
            1050 => 'DB_ERROR_TABLE_ALREADY_EXISTS',
            1051 => 'DB_ERROR_NOSUCHTABLE',
            1054 => 'DB_ERROR_NOSUCHFIELD',
            1060 => 'DB_ERROR_COLUMN_ALREADY_EXISTS',
            1061 => 'DB_ERROR_KEY_NAME_ALREADY_EXISTS',
            1062 => 'DB_ERROR_RECORD_ALREADY_EXISTS',
            1064 => 'DB_ERROR_SYNTAX',
            1068 => 'DB_ERROR_PRIMARY_KEY_ALREADY_EXISTS',
            1075 => 'DB_ERROR_CANT_DROP_PRIMARY_KEY',
            1091 => 'DB_ERROR_NOSUCHFIELD',
            1100 => 'DB_ERROR_NOT_LOCKED',
            1136 => 'DB_ERROR_VALUE_COUNT_ON_ROW',
            1146 => 'DB_ERROR_NOSUCHTABLE',
            1216 => 'DB_ERROR_NO_PARENT',
            1217 => 'DB_ERROR_CHILD_EXISTS',
            1396 => 'DB_ERROR_USER_ALREADY_EXISTS',    // When creating user already existing
            1451 => 'DB_ERROR_CHILD_EXISTS'
            );

            if (isset($errorcode_map[mysqli_errno($this->db)]))
            {
                return $errorcode_map[mysqli_errno($this->db)];
            }
            $errno=mysqli_errno($this->db);
            return ($errno?'DB_ERROR_'.$errno:'0');
        }
    }

    /**
	 *	Return description of last error
	 *
	 *	@return	string		Error text
     */
    function error()
    {
        if (! $this->connected) {
            // Si il y a eu echec de connexion, $this->db n'est pas valide pour mysqli_error.
            return 'Not connected. Check setup parameters in conf/conf.php file and your mysql client and server versions';
        }
        else {
            return mysqli_error($this->db);
        }
    }

    /**
	 * Get last ID after an insert INSERT
	 *
	 * @param   string	$tab    	Table name concerned by insert. Ne sert pas sous MySql mais requis pour compatibilite avec Postgresql
	 * @param	string	$fieldid	Field name
	 * @return  int     			Id of row
     */
    function last_insert_id($tab,$fieldid='rowid')
    {
        return mysqli_insert_id($this->db);
    }

    /**
     *	Encrypt sensitive data in database
     *  Warning: This function includes the escape, so it must use direct value
     *
     *	@param	string	$fieldorvalue	Field name or value to encrypt
     * 	@param	int		$withQuotes		Return string with quotes
     * 	@return	string					XXX(field) or XXX('value') or field or 'value'
     *
     */
    function encrypt($fieldorvalue, $withQuotes=0)
    {
        global $conf;

        // Type of encryption (2: AES (recommended), 1: DES , 0: no encryption)
        $cryptType = (!empty($conf->db->dolibarr_main_db_encryption)?$conf->db->dolibarr_main_db_encryption:0);

        //Encryption key
        $cryptKey = (!empty($conf->db->dolibarr_main_db_cryptkey)?$conf->db->dolibarr_main_db_cryptkey:'');

        $return = ($withQuotes?"'":"").$this->escape($fieldorvalue).($withQuotes?"'":"");

        if ($cryptType && !empty($cryptKey))
        {
            if ($cryptType == 2)
            {
                $return = 'AES_ENCRYPT('.$return.',\''.$cryptKey.'\')';
            }
            else if ($cryptType == 1)
            {
                $return = 'DES_ENCRYPT('.$return.',\''.$cryptKey.'\')';
            }
        }

        return $return;
    }

    /**
     *	Decrypt sensitive data in database
     *
     *	@param	string	$value			Value to decrypt
     * 	@return	string					Decrypted value if used
     */
    function decrypt($value)
    {
        global $conf;

        // Type of encryption (2: AES (recommended), 1: DES , 0: no encryption)
        $cryptType = (!empty($conf->db->dolibarr_main_db_encryption)?$conf->db->dolibarr_main_db_encryption:0);

        //Encryption key
        $cryptKey = (!empty($conf->db->dolibarr_main_db_cryptkey)?$conf->db->dolibarr_main_db_cryptkey:'');

        $return = $value;

        if ($cryptType && !empty($cryptKey))
        {
            if ($cryptType == 2)
            {
                $return = 'AES_DECRYPT('.$value.',\''.$cryptKey.'\')';
            }
            else if ($cryptType == 1)
            {
                $return = 'DES_DECRYPT('.$value.',\''.$cryptKey.'\')';
            }
        }

        return $return;
    }


    /**
	 * Return connexion ID
	 *
	 * @return	        string      Id connexion
     */
    function DDLGetConnectId()
    {
        $resql=$this->query('SELECT CONNECTION_ID()');
        $row=$this->fetch_row($resql);
        return $row[0];
    }

    /**
	 *	Create a new database
	 *	Do not use function xxx_create_db (xxx=mysql, ...) as they are deprecated
	 *	We force to create database with charset this->forcecharset and collate this->forcecollate
	 *
	 *	@param	string	$database		Database name to create
	 * 	@param	string	$charset		Charset used to store data
	 * 	@param	string	$collation		Charset used to sort data
	 * 	@param	string	$owner			Username of database owner
	 * 	@return	resource				resource defined if OK, null if KO
     */
    function DDLCreateDb($database,$charset='',$collation='',$owner='')
    {
        if (empty($charset))   $charset=$this->forcecharset;
        if (empty($collation)) $collation=$this->forcecollate;

        // ALTER DATABASE dolibarr_db DEFAULT CHARACTER SET latin DEFAULT COLLATE latin1_swedish_ci
		$sql = "CREATE DATABASE `".$this->escape($database)."`";
		$sql.= " DEFAULT CHARACTER SET `".$this->escape($charset)."` DEFAULT COLLATE `".$this->escape($collation)."`";

        dol_syslog($sql,LOG_DEBUG);
        $ret=$this->query($sql);
        if (! $ret)
        {
            // We try again for compatibility with Mysql < 4.1.1
            $sql = "CREATE DATABASE `".$this->escape($database)."`";
            dol_syslog($sql,LOG_DEBUG);
            $ret=$this->query($sql);
        }
        return $ret;
    }

    /**
	 *  List tables into a database
	 *
	 *  @param	string		$database	Name of database
	 *  @param	string		$table		Nmae of table filter ('xxx%')
	 *  @return	resource				Resource
     */
    function DDLListTables($database, $table='')
    {
        $listtables=array();

        $like = '';
        if ($table) $like = "LIKE '".$table."'";
        $sql="SHOW TABLES FROM ".$database." ".$like.";";
        //print $sql;
        $result = $this->query($sql);
        while($row = $this->fetch_row($result))
        {
            $listtables[] = $row[0];
        }
        return $listtables;
    }

    /**
	 *	List information of columns into a table.
	 *
	 *	@param	string	$table		Name of table
	 *	@return	array				Tableau des informations des champs de la table
     */
    function DDLInfoTable($table)
    {
        $infotables=array();

        $sql="SHOW FULL COLUMNS FROM ".$table.";";

        dol_syslog($sql,LOG_DEBUG);
        $result = $this->query($sql);
        while($row = $this->fetch_row($result))
        {
            $infotables[] = $row;
        }
        return $infotables;
    }

    /**
	 *	Create a table into database
	 *
	 *	@param	    string	$table 			Nom de la table
	 *	@param	    array	$fields 		Tableau associatif [nom champ][tableau des descriptions]
	 *	@param	    string	$primary_key 	Nom du champ qui sera la clef primaire
	 *	@param	    string	$type 			Type de la table
	 *	@param	    array	$unique_keys 	Tableau associatifs Nom de champs qui seront clef unique => valeur
	 *	@param	    array	$fulltext_keys	Tableau des Nom de champs qui seront indexes en fulltext
	 *	@param	    string	$keys 			Tableau des champs cles noms => valeur
	 *	@return	    int						<0 if KO, >=0 if OK
     */
    function DDLCreateTable($table,$fields,$primary_key,$type,$unique_keys="",$fulltext_keys="",$keys="")
    {
        // cles recherchees dans le tableau des descriptions (fields) : type,value,attribute,null,default,extra
        // ex. : $fields['rowid'] = array('type'=>'int','value'=>'11','null'=>'not null','extra'=> 'auto_increment');
        $sql = "CREATE TABLE ".$table."(";
        $i=0;
        foreach($fields as $field_name => $field_desc)
        {
        	$sqlfields[$i] = $field_name." ";
			$sqlfields[$i]  .= $field_desc['type'];
			if( preg_match("/^[^\s]/i",$field_desc['value'])) {
				$sqlfields[$i]  .= "(".$field_desc['value'].")";
			}
			if( preg_match("/^[^\s]/i",$field_desc['attribute'])) {
				$sqlfields[$i]  .= " ".$field_desc['attribute'];
			}
			if( preg_match("/^[^\s]/i",$field_desc['default']))
			{
				if ((preg_match("/null/i",$field_desc['default'])) || (preg_match("/CURRENT_TIMESTAMP/i",$field_desc['default']))) {
					$sqlfields[$i]  .= " default ".$field_desc['default'];
				}
				else {
					$sqlfields[$i]  .= " default '".$field_desc['default']."'";
				}
			}
			if( preg_match("/^[^\s]/i",$field_desc['null'])) {
				$sqlfields[$i]  .= " ".$field_desc['null'];
			}
			if( preg_match("/^[^\s]/i",$field_desc['extra'])) {
				$sqlfields[$i]  .= " ".$field_desc['extra'];
			}
            $i++;
        }
        if($primary_key != "")
        $pk = "primary key(".$primary_key.")";

        if($unique_keys != "")
        {
            $i = 0;
            foreach($unique_keys as $key => $value)
            {
                $sqluq[$i] = "UNIQUE KEY '".$key."' ('".$value."')";
                $i++;
            }
        }
        if($keys != "")
        {
            $i = 0;
            foreach($keys as $key => $value)
            {
                $sqlk[$i] = "KEY ".$key." (".$value.")";
                $i++;
            }
        }
        $sql .= implode(',',$sqlfields);
        if($primary_key != "")
        $sql .= ",".$pk;
        if($unique_keys != "")
        $sql .= ",".implode(',',$sqluq);
        if($keys != "")
        $sql .= ",".implode(',',$sqlk);
        $sql .=") engine=".$type;

        dol_syslog($sql,LOG_DEBUG);
        if(! $this -> query($sql))
        return -1;
        else
        return 1;
    }

    /**
	 *	Return a pointer of line with description of a table or field
	 *
	 *	@param	string		$table	Name of table
	 *	@param	string		$field	Optionnel : Name of field if we want description of field
	 *	@return	resultset			Resultset x (x->Field, x->Type, ...)
     */
    function DDLDescTable($table,$field="")
    {
        $sql="DESC ".$table." ".$field;

        dol_syslog(get_class($this)."::DDLDescTable ".$sql,LOG_DEBUG);
        $this->_results = $this->query($sql);
        return $this->_results;
    }

    /**
	 *	Create a new field into table
	 *
	 *	@param	string	$table 				Name of table
	 *	@param	string	$field_name 		Name of field to add
	 *	@param	string	$field_desc 		Tableau associatif de description du champ a inserer[nom du parametre][valeur du parametre]
	 *	@param	string	$field_position 	Optionnel ex.: "after champtruc"
	 *	@return	int							<0 if KO, >0 if OK
     */
    function DDLAddField($table,$field_name,$field_desc,$field_position="")
    {
        // cles recherchees dans le tableau des descriptions (field_desc) : type,value,attribute,null,default,extra
        // ex. : $field_desc = array('type'=>'int','value'=>'11','null'=>'not null','extra'=> 'auto_increment');
        $sql= "ALTER TABLE ".$table." ADD `".$field_name."` ";
        $sql.= $field_desc['type'];
        if(preg_match("/^[^\s]/i",$field_desc['value']))
        if (! in_array($field_desc['type'],array('date','datetime')))
        {
            $sql.= "(".$field_desc['value'].")";
        }
        if(preg_match("/^[^\s]/i",$field_desc['attribute']))
        $sql.= " ".$field_desc['attribute'];
        if(preg_match("/^[^\s]/i",$field_desc['null']))
        $sql.= " ".$field_desc['null'];
        if(preg_match("/^[^\s]/i",$field_desc['default']))
        {
            if(preg_match("/null/i",$field_desc['default']))
            $sql.= " default ".$field_desc['default'];
            else
            $sql.= " default '".$field_desc['default']."'";
        }
        if(preg_match("/^[^\s]/i",$field_desc['extra']))
        $sql.= " ".$field_desc['extra'];
        $sql.= " ".$field_position;

        dol_syslog(get_class($this)."::DDLAddField ".$sql,LOG_DEBUG);
        if(! $this->query($sql))
        {
            return -1;
        }
        else
        {
            return 1;
        }
    }

    /**
	 *	Update format of a field into a table
	 *
	 *	@param	string	$table 				Name of table
	 *	@param	string	$field_name 		Name of field to modify
	 *	@param	string	$field_desc 		Array with description of field format
	 *	@return	int							<0 if KO, >0 if OK
     */
    function DDLUpdateField($table,$field_name,$field_desc)
    {
        $sql = "ALTER TABLE ".$table;
        $sql .= " MODIFY COLUMN ".$field_name." ".$field_desc['type'];
        if ($field_desc['type'] == 'tinyint' || $field_desc['type'] == 'int' || $field_desc['type'] == 'varchar') {
        	$sql.="(".$field_desc['value'].")";
        }
        if ($field_desc['null'] == 'not null' || $field_desc['null'] == 'NOT NULL') $sql.=" NOT NULL";

        dol_syslog(get_class($this)."::DDLUpdateField ".$sql,LOG_DEBUG);
        if (! $this->query($sql))
        return -1;
        else
        return 1;
    }

    /**
	 *	Drop a field from table
	 *
	 *	@param	string	$table 			Name of table
	 *	@param	string	$field_name 	Name of field to drop
	 *	@return	int						<0 if KO, >0 if OK
     */
    function DDLDropField($table,$field_name)
    {
        $sql= "ALTER TABLE ".$table." DROP COLUMN `".$field_name."`";
        dol_syslog(get_class($this)."::DDLDropField ".$sql,LOG_DEBUG);
        if (! $this->query($sql))
        {
            $this->error=$this->lasterror();
            return -1;
        }
        else return 1;
    }


    /**
	 * 	Create a user and privileges to connect to database (even if database does not exists yet)
	 *
	 *	@param	string	$dolibarr_main_db_host 		Ip serveur
	 *	@param	string	$dolibarr_main_db_user 		Nom user a creer
	 *	@param	string	$dolibarr_main_db_pass 		Mot de passe user a creer
	 *	@param	string	$dolibarr_main_db_name		Database name where user must be granted
	 *	@return	int									<0 if KO, >=0 if OK
     */
    function DDLCreateUser($dolibarr_main_db_host,$dolibarr_main_db_user,$dolibarr_main_db_pass,$dolibarr_main_db_name)
    {
        $sql = "CREATE USER '".$this->escape($dolibarr_main_db_user)."'";
        dol_syslog(get_class($this)."::DDLCreateUser", LOG_DEBUG);	// No sql to avoid password in log
        $resql=$this->query($sql);
        if (! $resql)
        {
            if ($this->lasterrno != 'DB_ERROR_USER_ALREADY_EXISTS')
            {
            	dol_syslog(get_class($this)."::DDLCreateUser sql=".$sql, LOG_ERR);
            	return -1;
            }
            else
            {
            	// If user already exists, we continue to set permissions
            	dol_syslog(get_class($this)."::DDLCreateUser sql=".$sql, LOG_WARNING);
            }
        }
        $sql = "GRANT ALL PRIVILEGES ON ".$this->escape($dolibarr_main_db_name).".* TO '".$this->escape($dolibarr_main_db_user)."'@'".$this->escape($dolibarr_main_db_host)."' IDENTIFIED BY '".$this->escape($dolibarr_main_db_pass)."'";
        dol_syslog(get_class($this)."::DDLCreateUser", LOG_DEBUG);	// No sql to avoid password in log
        $resql=$this->query($sql);
        if (! $resql)
        {
            dol_syslog(get_class($this)."::DDLCreateUser sql=".$sql, LOG_ERR);
            return -1;
        }

        $sql="FLUSH Privileges";

        dol_syslog(get_class($this)."::DDLCreateUser sql=".$sql);
        $resql=$this->query($sql);
        if (! $resql)
        {
            dol_syslog(get_class($this)."::DDLCreateUser sql=".$sql, LOG_ERR);
            return -1;
        }

        return 1;
    }

    /**
     *	Return charset used to store data in database
     *
     *	@return		string		Charset
     */
    function getDefaultCharacterSetDatabase()
    {
        $resql=$this->query('SHOW VARIABLES LIKE \'character_set_database\'');
        if (!$resql)
        {
            // version Mysql < 4.1.1
            return $this->forcecharset;
        }
        $liste=$this->fetch_array($resql);
        return $liste['Value'];
    }

    /**
     *	Return list of available charset that can be used to store data in database
     *
     *	@return		array		List of Charset
     */
    function getListOfCharacterSet()
    {
        $resql=$this->query('SHOW CHARSET');
        $liste = array();
        if ($resql)
        {
            $i = 0;
            while ($obj = $this->fetch_object($resql) )
            {
                $liste[$i]['charset'] = $obj->Charset;
                $liste[$i]['description'] = $obj->Description;
                $i++;
            }
            $this->free($resql);
        } else {
            // version Mysql < 4.1.1
            return null;
        }
        return $liste;
    }

    /**
     *	Return collation used in database
     *
     *	@return		string		Collation value
     */
    function getDefaultCollationDatabase()
    {
        $resql=$this->query('SHOW VARIABLES LIKE \'collation_database\'');
        if (!$resql)
        {
            // version Mysql < 4.1.1
            return $this->forcecollate;
        }
        $liste=$this->fetch_array($resql);
        return $liste['Value'];
    }

    /**
     *	Return list of available collation that can be used for database
     *
     *	@return		array		Liste of Collation
     */
    function getListOfCollation()
    {
        $resql=$this->query('SHOW COLLATION');
        $liste = array();
        if ($resql)
        {
            $i = 0;
            while ($obj = $this->fetch_object($resql) )
            {
                $liste[$i]['collation'] = $obj->Collation;
                $i++;
            }
            $this->free($resql);
        } else {
            // version Mysql < 4.1.1
            return null;
        }
        return $liste;
    }

    /**
	 *	Return full path of dump program
	 *
	 *	@return		string		Full path of dump program
     */
    function getPathOfDump()
    {
        $fullpathofdump='/pathtomysqldump/mysqldump';

        $resql=$this->query('SHOW VARIABLES LIKE \'basedir\'');
        if ($resql)
        {
            $liste=$this->fetch_array($resql);
            $basedir=$liste['Value'];
            $fullpathofdump=$basedir.(preg_match('/\/$/',$basedir)?'':'/').'bin/mysqldump';
        }
        return $fullpathofdump;
    }

    /**
     *	Return full path of restore program
     *
     *	@return		string		Full path of restore program
     */
    function getPathOfRestore()
    {
        $fullpathofimport='/pathtomysql/mysql';

        $resql=$this->query('SHOW VARIABLES LIKE \'basedir\'');
        if ($resql)
        {
            $liste=$this->fetch_array($resql);
            $basedir=$liste['Value'];
            $fullpathofimport=$basedir.(preg_match('/\/$/',$basedir)?'':'/').'bin/mysql';
        }
        return $fullpathofimport;
    }

    /**
     * Return value of server parameters
     *
     * @param	string	$filter		Filter list on a particular value
	 * @return	array				Array of key-values (key=>value)
     */
    function getServerParametersValues($filter='')
    {
        $result=array();

        $sql='SHOW VARIABLES';
        if ($filter) $sql.=" LIKE '".$this->escape($filter)."'";
        $resql=$this->query($sql);
        if ($resql)
        {
        	while($obj=$this->fetch_object($resql)) $result[$obj->Variable_name]=$obj->Value;
        }

        return $result;
    }

    /**
     * Return value of server status (current indicators on memory, cache...)
     *
     * @param	string	$filter		Filter list on a particular value
	 * @return  array				Array of key-values (key=>value)
     */
    function getServerStatusValues($filter='')
    {
        $result=array();

        $sql='SHOW STATUS';
        if ($filter) $sql.=" LIKE '".$this->escape($filter)."'";
        $resql=$this->query($sql);
        if ($resql)
        {
            while($obj=$this->fetch_object($resql)) $result[$obj->Variable_name]=$obj->Value;
        }

        return $result;
    }
}