PHP While Loop从数据库中获取数据

I'm building a mobile application that requires push notifications to be sent whenever a new post is added.

Here's the PHP notification script: (it should be added inside the loop so it will be used again for each result.

$to = (should get DEVICEID from the database).
$title = "A new request"
sendPush($to,$title,$message);
function sendPush($to,$title,$message){
  //Sends noti.
}

So How do I place the above code in a while loop, and get the DEVICEID from the database and place it into $to ?

I suppose that you have an mysql connection set up and that you are using mysqli.

After you have created the connection to the database, you should have a variable holding your connection:

$con = mysqli_connect("localhost","my_user","my_password","my_db");

// Check connection
if (mysqli_connect_errno())
{
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

So right now you are able to execute a SQL statement to your database. Your SQL statement should look similarily to this:

$sql = "SELECT DeviceID FROM Devices";

Now we can execute the statement we created to the database:

$result = mysqli_execute($con, $sql);

Now we get a result object. We can use this to get a while loop:

while ($row = mysqli_fetch_assoc($result)) {
    $to = $row["DeviceID"];
    // Rest of your code, this will be executed for every DeviceID in the database.
}

If you are using PDO you can read more about it here: http://php.net/manual/en/ref.pdo-mysql.php

But in general, the steps are the same.