[cant get php to connect with mysql]

you don't declare a db in your connect statement

[code]
<?php
$sv = localhost;
$un = username;
$pw = password;
$db = database;


$link = mysqli_connect("$sv", "$un", "$pw", "$db");
?>

[Grouping listed items]

[!--quoteo(post=341624:date=Jan 31 2006, 05:03 PM:name=wickning1)--][div class=\'quotetop\']QUOTE(wickning1 @ Jan 31 2006, 05:03 PM) [snapback]341624[/snapback][/div][div class=\'quotemain\'][!--quotec--]
I'm sorry I don't have much time to explain but here's a rough idea of how I would determine the groups. Maybe it'll be a useful starting point for you.

Note that I have my own quick version of doing a mysql query, using $db->get() isn't going to work for you, but it should be clear what it's supposed to do for me.

[code]
<?php
$i = 0;
$oldmw = 0;
$count = $db->get("SELECT COUNT(*) FROM wrestlers");
while (count($used) <= $count) {
    $oldmw = $minw;
    $minw = $db->get("SELECT MIN(weight) FROM wrestlers WHERE weight > $oldmw");
    $group = $db->getall("SELECT * FROM wrestlers WHERE weight < $minw * 1.10 AND weight > $oldmw");
    echo "Group $i";
    foreach ($group as $wrestler) {
        echo $wrestler['Fname'] . " " . $wrestler['Lname'] . "<br>\n";
    }
    $i++;
}
?>
[/code]
[/quote]

thanks for the reply, you have the veriable $used in the while statement, but no place declares that variable. what is it?

[Grouping listed items]

ok comming back to this problem, been away from it for a while

this is my code

[code]
<?php

// attempting to figure out how to build with following logic

/*  Database is Populated with Wrestlers  of different weights
Starting from lightest weight  build tournement of round robins,
each round robin consisting of a Maximum of 4 people,  
that group of 4 can not differ in weight by more then 10%
*/

// connect to DB
include('unpw.php');
include('db.php');


// attepmted logic
// find and display  min weight

// $sql_kg = "SELECT * FROM wrestlers WHERE weight=(Select MIN(weight) FROM wrestlers) ORDER BY weight DESC";
$sql_kg = "SELECT * FROM wrestlers ORDER BY weight ASC";
$query = mysqli_query($link, $sql_kg);
echo "<table Border = 1>";
echo "<tr><td>First name</td><td>Last name</td><td> weight</td></tr>";
while($results = mysqli_fetch_array($query, MYSQLI_BOTH)) {

/*
reference for what each value is in the DB
$results[0] = ID
$results[1]  = Fname
$results[2] = Lname
$results[3] = Weight
$results[4] = gender
*/

// display contents of  db ordered by weight
printf("<tr><td>%s </td><td> %s</td><td>%s</td></tr>\n",
        $results[1], $results[2], $results[3]);

    
}
echo "</table>";

?>
[/code]



so this displays every ones weight great. correct order.

now how do I manipulate the results?

I want to compare the first $result[3] with the second $result[3] if they follow the criteria I want then I want to compare #3 result[3] with #1 result[3] if it follows the criteria then I want to compare #4 result[3] with #1 result[3] if it follows the criteria then I want to take #5result[3] and repeat what I just did from result 1 comparing the next 3 results.

the criteria is
#1 result[3] <= next result[3] + 10%

not sure how I want to store my groupings yet either in there own table in the DB or as a variable, probably there own DB.

thank you for the ongoing help,

[Grouping listed items]

ok

so I've had a crack at it for a bit and am lost

so I figured I would make the results generated from an SQL query an array then do mathematical operations on the weight field

so I tried this code
[code]
$sql_kg = "SELECT * FROM wrestlers ORDER BY weight DESC";
$query = mysqli_query($link, $sql_kg);
while ($r = mysqli_fetch_array($query, MYSQLI_BOTH) ) {
         $field1 = $r['Fname'];
         $field2 = $r['Lname'];
         $field3 = $r['weight'];
}
$w1 = array ($field1);
$w2 = array ($field2);
$w3 = array ($field3);


print "$w1[0].$w2[0].$w3[0] <br>";

[/code]

works fine there displays the lightest weight both name and weight

BUT if I add the line
[code]

print "$w1[1].$w2[1].$w3[1] <br>";
[/code]

beneath it I don't get the next lightest weight displayed.

got any advice? see any glaring holes in my idea?

thanks.

[Subquery in mysql versions.]

[!--quoteo(post=339083:date=Jan 23 2006, 06:26 AM:name=shan_cool)--][div class=\'quotetop\']QUOTE(shan_cool @ Jan 23 2006, 06:26 AM) [snapback]339083[/snapback][/div][div class=\'quotemain\'][!--quotec--]
Hi all,
I am using mysql 3.23.. it doesn't support subqueries... does mysql 4 supports it??? can anyone let me know..

rgds,
shan,
chennai..............
[/quote]


I am not sure about mySQL 4 and subqueries but mySQL 5 supports them

[a href=\"http://dev.mysql.com/doc/refman/5.0/en/subqueries.html\" target=\"_blank\"]http://dev.mysql.com/doc/refman/5.0/en/subqueries.html[/a]

[Grouping listed items]

if you notice in the logic if the weight is beyond 10% a new group starts,

if I had 3 guys with in a round robin class of 4 because the 4th would be too heavy, that forth is now the lightest weight in the next class up from that and the group of 3 rounds would look like this


Round 1
A + Sitout
C + D
Round 2
A + C
D + Sitout
Round 3
A + D
C + sitout.


my mySQL experience has been limited to forum modifications, and dealing with pre existing applications. I was hopeing that mySQL had the logic to do these groupings.

I guess I have to use PHP to do them, and just use mySQL to store the data


how should I go about getting the groups?

select * from wrestlers Order by weight (what expression would limit return by not having a difference of 10% )

should I store this grouping as a variable? then check for the last ID used and search from next ID for next group not differing by 10% max 4 people? and continue on this path?

thanks for the help thus far by the way.

[Grouping listed items]

[!--quoteo(post=338054:date=Jan 19 2006, 12:34 PM:name=fenway)--][div class=\'quotetop\']QUOTE(fenway @ Jan 19 2006, 12:34 PM) [snapback]338054[/snapback][/div][div class=\'quotemain\'][!--quotec--]
Making 6 groups is not a problem; neither is the NULL requirement. But how can you guarantee only a 10% difference? Please clarify.
[/quote]


Ok here is far more detail


The Program is going to be a leage meet generator for the Local Highschool wrestling program.

Each week the Wrestlers will be weighed and there info will be stored in the DB

id/Fname/Lname/weight/gender

after the tournement is over the db will be wiped and start fresh for the next week.

approx 100- 150 wrestlers weights between 38Kg and 150kg

the tournement is set up as a round robin, which is everyone will wrestle everyone in said weight class.

example of a 4 Person Round Robin

Round 1
A + B
C + D
Round 2
A + C
B+ D
Round 3
A + D
B + C

Since I have no Control over the exact weights I need to write a mathmatical equation to check to make sure that the heavest is not 10% > then the lightest in the group.

I figure the program will have to work like so for a 4 man round robin

Start from lightest weight.
> Select next lightest weight if < 10% difference add to RR if > 10% start new RR
> Select next lightest weight if < 10% difference from first guy in current RR add to RR, if > 10% add new RR
> Select next lighest weight if << 10% difference from first guy in current RR add to RR, if > 10% add new RR if current RR has 4 members start new RR


and so on. probably be a way to make it cleaner when I actually start thinking code rather then words.


I just need to figure out how to make the best SQL statements to minimize the transactions to the server with mySQL/PHP

[Undefined function: mysql_connect()]

[!--quoteo(post=337557:date=Jan 17 2006, 10:23 PM:name=doublew)--][div class=\'quotetop\']QUOTE(doublew @ Jan 17 2006, 10:23 PM) [snapback]337557[/snapback][/div][div class=\'quotemain\'][!--quotec--]
I'm trying to learn PHP and ran several simple tests that confirmed that PHP was working, but when I attempted to connect to a MySQL database, I got the following error message:

Fatal error: Call to undefined function: mysql_connect()

What would cause PHP to consider the mysql_connect() function to be undefined?

code:
$server = mysql_connect($host, $username, $password) or die(mysql_error());
[/quote]


you need to use mysqli_connect with mySQL 5.+

[a href=\"http://ca3.php.net/manual/en/function.mysqli-connect.php\" target=\"_blank\"]http://ca3.php.net/manual/en/function.mysqli-connect.php[/a]

[Grouping listed items]

Hello

I am looking to make a program that will fetch info from a db and sort it for me as such


the DB has 1 table 5 fields
id, Fname, Lname, weight, Gender

I want to group by gender, and weight,

groups of 6, the weight difference between the heaviest and the lightest in the group of 6 can not be greater then 10%

in the event a group can not be built following these criteria a NULL value is to be inserted making groups of 4 or 5 with 1 or 2 NULL's



I'm pretty sure I'll be able to figure out how to display them in a round robin style format once I get help figure out how to do the queries, should I be storeing info in a temporary table? please any help would be great.