Show random element

Suppose you have same news website and you want to show random news the homepage.

Using MySQL this can be done with "select - order by rand() limit 1". Because of "order by rand()" MySQL server must do full table scan. If table is big, this may take ages.

Here is how this may be done with Redis, using previous data structure

$r = new Redis();
$r->connect("127.0.0.1", "6379");

$newsroom = "sport";
$key = "news:" . $newsroom;

//Get random item...
$item = $r->lindex($key, rand(0, $r->llen($key) - 1));

echo $item;

Redis connection note

The example uses generic connection to the Redis server. To make the example work with our service you will need to use code similar to this one:

// change these parameter according to the information in your instance list
$host = '85.25.11.9';
$port = 1234;
$password = 'somehashcode';
$db = 0;

$r = new Redis();
$r->connect($host, $port);
$r->auth($password);
$r->select($db);

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Code library

Note:
Because we want this page to be useful for memcached users, we tagged with memcached all examples that may be "recreated" for memcached server.


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