Grouping Mysql PHP Query Results - php

Question

I have a basic PHP page which searches a MySQL Database of retro ZX Spectrum magazine articles.
The address is [www.retroresource.co.uk][1]
The PHP Results Page is fine, in that it produced the results, but I would like to be able to group the results by 'fgames.fgname'
So for example if I searched for Dizzy
Dizzy (as a header)
Table with rows that have fgames.fgname = Dizzy
Spindizzy (as a header)
Table with rows that have fgames.fgname = Spindizzy
Treasure Island Dizzy (as a header)
Table with rows that have fgames.fgname = Treasure Island Dizzy
etc etc
I have googled and looked in a few of my text books, but am unable to see a solution. Any help much appreciated.
Peter
Amended Code after assistance (No results though)
<?php
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);
require( '../connect_db.php' ) ;
$query = $_GET['query'];
$min_length = 4;
// you can set minimum length of the query if you want
$query = strip_tags($query);
$query = mysqli_real_escape_string ($dbc,$query);
$q = "SELECT fgames.fgname, fgames.fgprorg, fgames.fgprbud, fgames.fgratng, fgames.fgprdsk, ftypes.fttname, frefs.fryymm, frefs.frpage, frefs.frissue, fmagzne.fmname, frefcde.ffname
FROM fgames, ftypes,frefs, fmagzne,frefcde
WHERE ftypes.fttype = fgames.fgtype
and fgames.fglink = frefs.frlink2
and frefs.frentry = frefcde.ffentry
and frefs.frmag = fmagzne.fmmag
and fgames.fgname LIKE '%".$query."%'
order by fgames.fgname ASC" ;
$r = mysqli_query( $dbc , $q ) ;
$current_group = '';
while ( $row = mysqli_fetch_array( $r , MYSQLI_ASSOC ) )
{
if($row['fgames.fgname']) !== $current_group)
{
if($current_group !== '')
{
echo '</table>';
}
$current_group = $row['fgames.fgname'];
echo '<table><tr><th>FGNAME</th><th>FGPRORG</th><th>FGRBUD</th><th>FGRATNG</th><th>FGRDSK</th>
<th>FTTTNAME</th><th>FRYYMM</th><th>FRPAGE</th><th>FRISSUE</th><th>FMNAME</th><th>FFNAME</th></tr>';
}
echo '<tr><td>'.$row['fgname'].'</td><td>'.$row['fgprorg'].'</td><td> '.$row['fgprbud'].' </td><td>'.$row['fgratng'].' </td> <td>'.$row['fgprdsk'].' </td><td>'.$row['fttname'].'</td><td> '.$row['fryymm'].'</td><td> '.$row['frpage'].'</td><td> '.$row['frissue'].' </td> <td>'.$row['fmname'].' </td><td>'.$row['ffname'].'</td></tr>';
}
echo '</table>';
else
{
echo '<p>' . mysqli_error( $dbc ) . '</p>' ;
}
# Close the connection.
mysqli_close( $dbc ) ;
?>

Answer 1

There are two basic approaches.
Either load the query data into a two dimensional array and output with nested loop like this:
$array_for_output = array();
while($row = /* your query fetch mechanism here */) {
$array_for_output[$row['field_you_are_grouping_on']] = $row;
}
foreach($array_for_output as $table_name => $table_data) {
// output table header here
foreach($table_data as $table_row) {
// output individual row
}
// output table closure here
}
Or the other approach is to query using an ORDER BY clause on the field you are trying to group by and detect changes in the current group in single loop
$query = "
SELECT ...
FROM ...
WHERE ...
ORDER BY field_you_are_grouping_on, any_secondary_ordering_field_here ASC";
// execute query here
$current_group = '';
while ($row = /* your query fetch mechanism here */) {
if($row['field_you_are_grouping_on']) !== $current_group) {
// we have started a new group
if($current_group !== '') {
// this is not first table
// so output closure to previous table here
}
$current_group = $row['field_you_are_grouping_on'];
// output new table header here
}
// output row data here
}
// output closure to final table here
The second approach is usually preferable from a memory management standpoint (you don't have to store entire result set in memory at any point), but some beginning developers may not find this not as intuitive as the first method. The first method also may be more appropriate if you want to take the full result set and inject it into some sort of template that is used to render the display.