PHP / MySQL - List who recruited whom - php

Question

i'am working on a social project and we've just startet the registration for members.
Our members could recriute new members, so we have a database where is a field "recruit_by".
The DB fiels looks like this:
id | name | email | code | recruit_by
We now want to generate a list of the structure, who recruited whom on all levels.
I've tried to get this done, but it seems my skills are to less to get this done.
I get a list, but this is totaly unsorted :-(
Thanks for your help!
<?PHP
mysql_connect("www.mysqlserver.net", "database1", "password") or die(mysql_error());
mysql_select_db("project_db1") or die(mysql_error());
echo "<ul>";
$result = mysql_query("SELECT * FROM registration") or die(mysql_error());
while($row = mysql_fetch_array($result))
{
echo "<li class=\"level0\">" . $row['id'] . " - " . $row['name'] . " - " . $row['email'] . " - " . $row['recruit_by'] . "</li>";
// 1. Level
$result2 = mysql_query("SELECT * FROM registration WHERE recruit_by LIKE " . $row['id']) or die(mysql_error());
while($row2 = mysql_fetch_array($result2))
{
echo "<li class=\"level1\">1. " . $row2['id'] . " - " . $row2['name'] . " - " . $row2['email'] . " - " . $row2['recruit_by'] . "</li>";
// 2. Level
$result3 = mysql_query("SELECT * FROM registration WHERE recruit_by LIKE " . $row2['id']) or die(mysql_error());
while($row3 = mysql_fetch_array($result3))
{
echo "<li class=\"level2\">2. " . $row3['id'] . " - " . $row3['name'] . " - " . $row3['email'] . " - " . $row3['recruit_by'] . "</li>";
// 3. Level
$result4 = mysql_query("SELECT * FROM registration WHERE recruit_by LIKE " . $row3['id']) or die(mysql_error());
while($row4 = mysql_fetch_array($result4))
{
echo "<li class=\"level3\">3. " . $row4['id'] . " - " . $row4['name'] . " - " . $row4['email'] . " - " . $row4['recruit_by'] . "</li>";
// 4. Level
$result5 = mysql_query("SELECT * FROM registration WHERE recruit_by LIKE " . $row4['id']) or die(mysql_error());
while($row5 = mysql_fetch_array($result5))
{
echo "<li class=\"level4\">4. " . $row5['id'] . " - " . $row5['name'] . " - " . $row5['email'] . " - " . $row5['recruit_by'] . "</li>";
}
}
}
}
}
echo "</ul>";
?>

Answer 1

First, you are selecting all registrations, that results all the recuited users also.
I would suggest selecting only non-recuited users, assuming recruit_by is NULL, when this user is not recruited:
$result = mysql_query("SELECT * FROM registration WHERE recruit_by IS NULL") or die(mysql_error());
Secondly it is good to structure second level of recruits in another <ul></ul> tags like this:
<ul>
<li>User #1
<ul>
<li>User #103, recruited by user #1</li>
<li>User #142, recruited by user #1</li>
<li>User #93, recruited by user #1
<ul>
<li>User #992, recruited by user #93</li>
</ul>
</li>
</ul>
</li>
</ul>
This already gives you much better structure to work with and you can easily loop it in you PHP code (DRY - don't repeat yourself).
<?php
function createTree($level = 0, $recruiter_id = 0) {
$return = "";
if (!$recruiter_id) {
$results = mysql_query("SELECT * FROM registration WHERE recruit_by IS NULL") or die(mysql_error());
} else {
$results = mysql_query("SELECT * FROM registration WHERE recruit_by LIKE " . $recruiter_id) or die(mysql_error());
}
// Check if there is any recruits at all?
if (pg_num_rows($results) > 0) $return .= "<ul>\n";
else return "";
while ($row = mysql_fetch_array($results)) {
$return .= "<li class=\"level".$level."\">\n";
$return .= $level.". " . $row['id'] . " - " . $row['name'] . " - " . $row['email'] . " - " . $row['recruit_by']."\n";
// Add sub-recruits
$return .= createTree($level+1, $row['id']);
// Finish up the <li>
$return .= "</li>\n";
}
$return .= "</ul>\n";
return $return;
}
?>