修改数据预处理语句函数的创建及使用

function update($tn,$data=array(),$w=‘1=1‘){
	 global $m;
	$ty = ‘‘;
	foreach($data as $k=>$v){
	    $kk[] = $k.‘=?‘;
		$dd[] = "\$data[‘$k‘]";
		switch(gettype($v)){
		    case ‘integer‘:$ty.=‘i‘;break;
			case ‘string‘:$ty.=‘s‘;	break;
			case ‘double‘:$ty.=‘d‘;break;
			default:$ty.=‘b‘;break;
		}
	}
	$vvv = implode(‘,‘,$dd);
	$bind = "\$stmt->bind_param(‘$ty‘,$vvv);";
	$key = implode(‘,‘,$kk);
	$stmt = $m->prepare("update $tn set  $key where $w");
    eval($bind);
    $stmt->execute();
	$stmt->free_result();
	$stmt->close();
}