I have a SQL database that contains a field. I can get all of the elements in that field by:
$result=mysql_query($sql);
while($row=mysql_fetch_array($result)){
$ftype =$row['ftype']; //name of field is 'ftype'
print $ftype} //do something
I want a random element to be printed out each time the page is opened/refreshed.
Knowing that the result is an array containing the information i want, I want to randomly choose an element of the array. Also, if there are N elements in the array, I want to choose all N elements exactly once before I show any element again for second time. The process repeats itself. I know how to code something like this in java or python, but I don't think that's the way I should go.
I think I need to use javascript, but I'm just not sure what technology to use.
UPDATE:
Patrick's 开发者_StackOverflowidea seems to be exactly what i was looking for. I thought I would share what I have now and maybe you can suggest optimization. I hope the intent in the code is obvious.
<?
session_start();
if (!isset($_SESSION['count']) || !isset($_SESSION['randomArray'])) {
$count = 0;
$randomArray = array();
$sql="SELECT youtubeurl FROM Foodlist";
$result=mysql_query($sql);
while($row=mysql_fetch_array($result)){
array_push($randomArray,$row['youtubeurl']);
}
shuffle($randomArray);
$_SESSION['randomArray'] = $randomArray;
$_SESSION['count'] = $count;
} elseif ($_SESSION['count'] >= sizeof($_SESSION['randomArray'])){
$_SESSION['count'] = 0;
$randomArray = $_SESSION['randomArray'];
shuffle($randomArray);
$_SESSION['randomArray'] = $randomArray;
} else{
$randomArray = $_SESSION['randomArray'];
$count = $_SESSION['count'];
echo $randomArray[$count];
$_SESSION['count']++;
}
?>
You can do this without Javascript, however you'll need to open/maintain a session.
Pseudocode:
data = data_from_mysql()
choice = random.choice(data, exclude = SESSION['choices'])
SESSION['choices'].append(choice)
print choice
if len(SESSION['choices']) == len(data):
SESSION['choices'] = []
If you want a random result let the dbms take care of it. Add this to the bottom of your sql query.
ORDER BY RAND()
LIMIT 1
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