Help me Select 10 unique players from database and 3 reseve for each one

custombrands

I have one row (ID). From ID i need to extract/select 10 primary ID's with 3 secondary ID for each one. There is one more condition! Every primary ID must be first selection! After we selected the first 10 (random unique id) i need to select 3 (random unique id) as reserves for each one. Example:

player1 (random unique id)
reserve1 (for player1) - (random unique id)
reserve2 (for player1) - (random unique id)
reserve3 (for player1) - (random unique id)
player2 (random unique id)
reserve1 (for player2) - (random unique id)
reserve2 (for player2) - (random unique id)
reserve3 (for player2) - (random unique id)
player3 (random unique id)

reserve1 (for player3) - (random unique id)
reserve2 (for player3) - (random unique id)
reserve3 (for player3) - (random unique id)
player4 (random unique id)

reserve1 (for player4) - (random unique id)
reserve2 (for player4) - (random unique id)
reserve3 (for player4) - (random unique id)
etc

Currently trying to use:

require_once "connect_to_mysql.php"; 
    $sqlCommand = "SELECT id FROM players ORDER BY RAND() LIMIT 10"; 
    $query = mysql_query($sqlCommand) or die (mysql_error());
    $i =1;
    while ($row = mysql_fetch_array($query)) { 
        echo "$i Player  = ";
        echo $row['id'];
        echo "<br />";
        echo 'Reserve'; 
        echo "<br />";
        if ($i % 5 == 0)
     {
       echo '<hr>';
     }
     $i++;
    }
    mysql_close();

dalecosp

How many players do you expect to have?

[thread=10338930]Order by Rand() is evil[/thread] ... might be better to get a list of ID's, pick some, and then get data about them....

Weedpacket

So you want to select forty IDs...

custombrands

not realy 40 but for each player i need 3 reserve!

Weedpacket

Ten players + three reserves for each player = 10 + 3 10 = 4 10 = 40. Or am I missing something? Reserves are not players? A player can be both a player and a reserve at the same time?

custombrands

i need to extract unique X (1 or 2 or ... 15) players with unique 3 reserves. every extracter player or reserves must be unique!
x is a value set after we need how many players are sign up!

custombrands

x is a value set after we know how many players are sign up!

custombrands

Selected player can not be seta as reserved

bradgrafelman

I still don't understand why Weedpacket's approach won't work. Forget the fact that you've got selected and reserve players. Just generate a result set of 40 IDs selected at random (for the ten players as suggested above).

Loop through the "selected" players by using a counter that starts at 0 and increments by 3. For each of those "selected" players, the two reserve players can be found at locations cur_row_num+1 and cur_row_num+2, respectively.

custombrands

bradgrafelman;11035153 wrote:
I still don't understand why Weedpacket's approach won't work. Forget the fact that you've got selected and reserve players. Just generate a result set of 40 IDs selected at random (for the ten players as suggested above).

Loop through the "selected" players by using a counter that starts at 0 and increments by 3. For each of those "selected" players, the two reserve players can be found at locations cur_row_num+1 and cur_row_num+2, respectively.

i'm not very good in php but i need to do my homework. can someone explain me how to do that?
best regards!