php数据库操作类(转)

<?php
Class DB {

    private $link_id ;
    private $handle ;
    private $is_log ;
    private $time ;

    //构造函数
    public function __construct() {
        $this ->time = $this ->microtime_float();
        require_once ( "config.db.php" );
        $this ->connect( $db_config [ "hostname" ], $db_config [ "username" ], $db_config [ "password" ], $db_config [ "database" ], $db_config [ "pconnect" ]);
        $this ->is_log = $db_config [ "log" ];
        if ( $this ->is_log){
            $handle = fopen ( $db_config [ "logfilepath" ]. "dblog.txt" , "a+" );
            $this ->handle= $handle ;
        }
    }

    //数据库连接
    public function connect( $dbhost , $dbuser , $dbpw , $dbname , $pconnect = 0, $charset = 'utf8' ) {
        if ( $pconnect ==0 ) {
            $this ->link_id = @mysql_connect( $dbhost , $dbuser , $dbpw , true);
            if (! $this ->link_id){
                $this ->halt( "数据库连接失败" );
            }
        } else {
            $this ->link_id = @mysql_pconnect( $dbhost , $dbuser , $dbpw );
            if (! $this ->link_id){
                $this ->halt( "数据库持久连接失败" );
            }
        }
        if (!@mysql_select_db( $dbname , $this ->link_id)) {
            $this ->halt( '数据库选择失败' );
        }
        @mysql_query( "set names " . $charset );
    }

    //查询
    public function query( $sql ) {
        $this ->write_log( "查询 " . $sql );
        $query = mysql_query( $sql , $this ->link_id);
        if (! $query ) $this ->halt( 'Query Error: ' . $sql );
        return $query ;
    }

    //获取一条记录（MYSQL_ASSOC，MYSQL_NUM，MYSQL_BOTH）
    public function get_one( $sql , $result_type = MYSQL_ASSOC) {
        $query = $this ->query( $sql );
        $rt =& mysql_fetch_array( $query , $result_type );
        $this ->write_log( "获取一条记录 " . $sql );
        return $rt ;
    }

    //获取全部记录
    public function get_all( $sql , $result_type = MYSQL_ASSOC) {
        $query = $this ->query( $sql );
        $i = 0;
        $rt = array ();
        while ( $row =& mysql_fetch_array( $query , $result_type )) {
            $rt [ $i ]= $row ;
            $i ++;
        }
        $this ->write_log( "获取全部记录 " . $sql );
        return $rt ;
    }

    //插入
    public function insert( $table , $dataArray ) {
        $field = "" ;
        $value = "" ;
        if ( ! is_array ( $dataArray ) || count ( $dataArray )<=0) {
            $this ->halt( '没有要插入的数据' );
            return false;
        }
        while (list( $key , $val )=each( $dataArray )) {
            $field .= "$key," ;
            $value .= "'$val'," ;
        }
        $field = substr ( $field ,0,-1);
        $value = substr ( $value ,0,-1);
        $sql = "insert into $table($field) values($value)" ;
        $this ->write_log( "插入 " . $sql );
        if (! $this ->query( $sql )) return false;
        return true;
    }

    //更新
    public function update( $table , $dataArray , $condition = "" ) {
        if ( ! is_array ( $dataArray ) || count ( $dataArray )<=0) {
            $this ->halt( '没有要更新的数据' );
            return false;
        }
        $value = "" ;
        while ( list( $key , $val ) = each( $dataArray ))
        $value .= "$key = '$val'," ;
        $value .= substr ( $value ,0,-1);
        $sql = "update $table set $value where 1=1 and $condition" ;
        $this ->write_log( "更新 " . $sql );
        if (! $this ->query( $sql )) return false;
        return true;
    }

    //删除
    public function delete ( $table , $condition = "" ) {
        if ( empty ( $condition ) ) {
            $this ->halt( '没有设置删除的条件' );
            return false;
        }
        $sql = "delete from $table where 1=1 and $condition" ;
        $this ->write_log( "删除 " . $sql );
        if (! $this ->query( $sql )) return false;
        return true;
    }

    //返回结果集
    public function fetch_array( $query , $result_type = MYSQL_ASSOC){
        $this ->write_log( "返回结果集" );
        return mysql_fetch_array( $query , $result_type );
    }

    //获取记录条数
    public function num_rows( $results ) {
        if (! is_bool ( $results )) {
            $num = mysql_num_rows( $results );
            $this ->write_log( "获取的记录条数为" . $num );
            return $num ;
        } else {
            return 0;
        }
    }

    //释放结果集
    public function free_result() {
        $void = func_get_args();
        foreach ( $void as $query ) {
            if ( is_resource ( $query ) && get_resource_type( $query ) === 'mysql result' ) {
                return mysql_free_result( $query );
            }
        }
        $this ->write_log( "释放结果集" );
    }

    //获取最后插入的id
    public function insert_id() {
        $id = mysql_insert_id( $this ->link_id);
        $this ->write_log( "最后插入的id为" . $id );
        return $id ;
    }

    //关闭数据库连接
    protected function close() {
        $this ->write_log( "已关闭数据库连接" );
        return @mysql_close( $this ->link_id);
    }

    //错误提示
    private function halt( $msg = '' ) {
        $msg .= "\r\n" .mysql_error();
        $this ->write_log( $msg );
        die ( $msg );
    }

    //析构函数
    public function __destruct() {
        $this ->free_result();
        $use_time = ( $this -> microtime_float())-( $this ->time);
        $this ->write_log( "完成整个查询任务,所用时间为" . $use_time );
        if ( $this ->is_log){
            fclose( $this ->handle);
        }
    }

    //写入日志文件
    public function write_log( $msg = '' ){
        if ( $this ->is_log){
            $text = date ( "Y-m-d H:i:s" ). " " . $msg . "\r\n" ;
            fwrite( $this ->handle, $text );
        }
    }

    //获取毫秒数
    public function microtime_float() {
        list( $usec , $sec ) = explode ( " " , microtime());
        return ((float) $usec + (float) $sec );
    }
}

?>

2. [代码]config.db.php     跳至 [1] [2] [全屏预览]

<?php
    $db_config [ "hostname" ] = "localhost" ; //服务器地址
    $db_config [ "username" ] = "root" ; //数据库用户名
    $db_config [ "password" ] = "123" ; //数据库密码
    $db_config [ "database" ] = "test" ; //数据库名称
    $db_config [ "charset" ] = "utf8" ; //数据库编码
    $db_config [ "pconnect" ] = 1; //开启持久连接
    $db_config [ "log" ] = 1; //开启日志
    $db_config [ "logfilepath" ] = './' ; //开启日志
?>