DiscuzX的mysql类

class db_mysql
{
    var $tablepre;
    var $version = '';
    var $querynum = 0;
    var $curlink;
    var $link = array();
    var $config = array();
    var $sqldebug = array();
    var $map = array();

    function db_mysql($config = array()) {
        if(!empty($config)) {
            $this->set_config($config);
        }
    }

    function set_config($config) {
        $this->config = &$config;
        $this->tablepre = $config['1']['tablepre'];
        if(!empty($this->config['map'])) {
            $this->map = $this->config['map'];
        }
    }

    function connect($serverid = 1) {

        if(empty($this->config) || empty($this->config[$serverid])) {
            $this->halt('config_db_not_found');
        }

        $this->link[$serverid] = $this->_dbconnect(
            $this->config[$serverid]['dbhost'],
            $this->config[$serverid]['dbuser'],
            $this->config[$serverid]['dbpw'],
            $this->config[$serverid]['dbcharset'],
            $this->config[$serverid]['dbname'],
            $this->config[$serverid]['pconnect']
            );
        $this->curlink = $this->link[$serverid];

    }

    function _dbconnect($dbhost, $dbuser, $dbpw, $dbcharset, $dbname, $pconnect) {
        $link = null;
        $func = empty($pconnect) ? 'mysql_connect' : 'mysql_pconnect';
        if(!$link = @$func($dbhost, $dbuser, $dbpw, 1)) {
            $this->halt('notconnect');
        } else {
            $this->curlink = $link;
            if($this->version() > '4.1') {
                $dbcharset = $dbcharset ? $dbcharset : $this->config[1]['dbcharset'];
                $serverset = $dbcharset ? 'character_set_connection='.$dbcharset.', character_set_results='.$dbcharset.', character_set_client=binary' : '';
                $serverset .= $this->version() > '5.0.1' ? ((empty($serverset) ? '' : ',').'sql_mode=\'\'') : '';
                $serverset && mysql_query("SET $serverset", $link);
            }
            $dbname && @mysql_select_db($dbname, $link);
        }
        return $link;
    }

    function table_name($tablename) {
        if(!empty($this->map) && !empty($this->map[$tablename])) {
            $id = $this->map[$tablename];
            if(!$this->link[$id]) {
                $this->connect($id);
            }
            $this->curlink = $this->link[$id];
        } else {
            $this->curlink = $this->link[1];
        }
        return $this->tablepre.$tablename;
    }

    function select_db($dbname) {
        return mysql_select_db($dbname, $this->curlink);
    }

    function fetch_array($query, $result_type = MYSQL_ASSOC) {
        return mysql_fetch_array($query, $result_type);
    }

    function fetch_first($sql) {
        return $this->fetch_array($this->query($sql));
    }

    function result_first($sql) {
        return $this->result($this->query($sql), 0);
    }

    function query($sql, $type = '') {

        if(defined('DISCUZ_DEBUG') && DISCUZ_DEBUG) {
            $starttime = dmicrotime();
        }
        $func = $type == 'UNBUFFERED' && @function_exists('mysql_unbuffered_query') ?
        'mysql_unbuffered_query' : 'mysql_query';
        if(!($query = $func($sql, $this->curlink))) {
            if(in_array($this->errno(), array(2006, 2013)) && substr($type, 0, 5) != 'RETRY') {
                $this->connect();
                return $this->query($sql, 'RETRY'.$type);
            }
            if($type != 'SILENT' && substr($type, 5) != 'SILENT') {
                $this->halt('query_error', $sql);
            }
        }

        if(defined('DISCUZ_DEBUG') && DISCUZ_DEBUG) {
            $this->sqldebug[] = array($sql, number_format((dmicrotime() - $starttime), 6), debug_backtrace());
        }

        $this->querynum++;
        return $query;
    }

    function affected_rows() {
        return mysql_affected_rows($this->curlink);
    }

    function error() {
        return (($this->curlink) ? mysql_error($this->curlink) : mysql_error());
    }

    function errno() {
        return intval(($this->curlink) ? mysql_errno($this->curlink) : mysql_errno());
    }

    function result($query, $row = 0) {
        $query = @mysql_result($query, $row);
        return $query;
    }

    function num_rows($query) {
        $query = mysql_num_rows($query);
        return $query;
    }

    function num_fields($query) {
        return mysql_num_fields($query);
    }

    function free_result($query) {
        return mysql_free_result($query);
    }

    function insert_id() {
        return ($id = mysql_insert_id($this->curlink)) >= 0 ? $id : $this->result($this->query("SELECT last_insert_id()"), 0);
    }

    function fetch_row($query) {
        $query = mysql_fetch_row($query);
        return $query;
    }

    function fetch_fields($query) {
        return mysql_fetch_field($query);
    }

    function version() {
        if(empty($this->version)) {
            $this->version = mysql_get_server_info($this->curlink);
        }
        return $this->version;
    }

    function close() {
        return mysql_close($this->curlink);
    }

    function halt($message = '', $sql = '') {
        require_once libfile('class/error');
        discuz_error::db_error($message, $sql);
    }

}