如何从mysql（最后到第一个顺序）获取数据和在JSON php中显示？

This is my Php file:

$sql = "SELECT * FROM sample";

$r = $conn->query($sql);
$result = array();

while($row = $r->fetch(PDO::FETCH_OBJ)){

   array_push($result,array(
   "title"=>$row->title
    ));
}
echo json_encode(array('result'=>$result));

This code fetches the data from my database and displays from first to last order, but I need to create a reverse order (from last to first). Please help.

Use SELECT * FROM sample ORDER BY ID DESC

ID is the column, according to which you want to order.

Add ORDER BY and your column name in your query, followed by DESC or ASC (descending or ascending, the latter being the default). For example:

$sql = "SELECT * FROM sample ORDER BY title DESC";