// 导出测试
    function explode() {
    	ob_end_clean();
    	header("Content-type:text/csv");
		header('Content-Disposition: attachment;filename=test_' . time() . '.csv');


		$fp = fopen('php://output', 'a');
		// 输出Excel列头信息
		$head = array('平台', '名称', '本金','时间');
		// foreach($head as $i => $v) {
		//     // CSV的Excel支持GBK编码，一定要转换，否则乱码
		//     $head[$i] = iconv('utf-8', 'GB2312//IGNORE', $v);
		// }
		fputcsv($fp, $head);

		$limit = 1000;
		$count = 1;
		$sql = 'select * from assets limit 0,1000';
		$rows = Db::table('表名')->query($sql);
		while(count($rows)>0 && $count<21) {
			$offset = $count*$limit;
		    $count++;

		    foreach ($rows as $key => $row) {
		    	if($key%2000 == 0) {
		    		if(ob_get_level()>0){
    					ob_flush() ;
		    		}
		    	}

		    	$val = array($row['platform'],$row['name'],$row['principal'],$row['create_time']);

		    	// foreach($val as $k => $v) {
		     //        $val[$k] = iconv('utf-8', 'GB2312//IGNORE', $v);
		     //    }

		        fputcsv($fp, $val);
		    }

		    $sql = "select * from assets limit {$offset},{$limit}";
			$rows = Db::table('表名')->query($sql);
		}
	}