How do I remove a row from mysql immediately after calling it? - mysql

Question

Basically, I have a mysql database where every time I get a row, I want to delete it from the database (after reading its information).
I know I could do something like
$result = mysql_query(" SELECT <some row> FROM table ");
$row = mysql_fetch_array($result);
$id = $row["id"];
mysqli_query(" DELETE FROM table WHERE id=$id");
but now it seems I have two queries going on. Is there a command to tell mysql that I want the row deleted as soon as it gives me the information? I imagine that'd save time and resources.
In my head, it looks like
$result = mysql_query(" SELECT <some row> FROM table THEN DELETE ");
EDIT additional information: I wish to use the SELECTed information after deleting the row. To put it simply, I only want one instance of the information to exist at any give time; it would be as if I were only "moving" a physical copy of the information, so that when it is put on a device/what have you, it is no longer in the table since there is only one copy.
Sorry if my understanding of mysql is rough -- I'm pretty new to it :P

Answer 1

I don't know why you need it but you can use a stored procedure for that:
DELIMITER $$
CREATE PROCEDURE select_and_delete(IN aid INT)
BEGIN
SELECT * FROM table1 WHERE id = aid;
DELETE FROM table1 WHERE id = aid;
END$$
DELIMITER ;
Here is SQLFiddle demo.
mysql_* extension is deprecated, therefore use prepared statements and mysqli or PDO.
Your php code using PDO might look like
$id = 1;
try {
$db = new PDO('mysql:host=localhost;dbname=test;charset=UTF8', 'user', 'userpwd');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$query = $db->prepare("CALL select_and_delete(?)");
$query->execute(array($id));
$result = $query->fetchAll(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
echo "Exception: " .$e->getMessage();
$result = false;
}
$query = null;
$db = null;
//do whatever you need to do with your resultset
var_dump($result);
Following a rather simplified table structure (with the only column id) presented in SQL Fiddle example if you call it with $id=1 you'll you'll get in $result:
array(1) {
[0]=>
array(1) {
["id"]=>
int(1)
}
}

Answer 2

You'll need to add a timestamp field (with default as CURRENT_TIMESTAMP) to be able to tell when the row was added.
Then you can run the following MySQL query.
DELETE FROM `table` WHERE `timestamp` > DATE_SUB(NOW(), INTERVAL 0 SECOND);
You will need to run this as a cron job though. AFAIK it can't be done in MySQL alone.