Array_unique和XLS导出

如何解决Array_unique和XLS导出

所以我想将数据库导出为XLS格式...这是我的代码

$req_test = $db->prepare('SELECT `surname`,`name`,`num`,`email`,`password`,`rank` FROM staff');
$req_test->execute();


$array = $req_test->fetchAll();

$array = array_unique($array);

print_r($array);


header("Content-disposition: attachment; filename=\"demo.xls\"");
header("Content-Type: application/vnd.ms-excel;");
header("Pragma: no-cache");
header("Expires: 0");
$out = fopen("PHP://output",'w');
foreach ($array as $data)
{
fputcsv($out,$data,"\t");
}
fclose($out);

因此，如果没有array_unique，它将返回以下内容：

Array ( [0] => Array ( [surname] => test [0] => test [name] => test [1] => test [num] => 2424242424 [2] => 2424242424 [email] => [e-mail] [3] => [e-mail] [password] => 123456 [4] => 123456 [rank] => admin [5] => admin ) [1] => Array ( [surname] => Markus [0] => Markus [name] => Tasse [1] => Tasse [num] => 052424524 [2] => 052424524 [email] => [e-mail] [3] => [e-mail] [password] => us01PjIOx2 [4] => us01PjIOx2 [rank] => staff [5] => staff ) ) 

有这个错误：

( ! ) Notice: Array to string conversion in C:\wamp3.2.0\www\project\export.PHP on line 15

我该怎么办？谢谢。