How PHP generates a tree-shaped list from database query results _php tips

This example describes how PHP generates a tree list from database query results. Share to everyone for your reference. The specific analysis is as follows:

This code can read data from a database to generate a tree-like List of Windows-similar resource managers

<?php/* Here are the database definitions (for Solid) which I use in this code.
 * It should not being hard to adapt it to another database.
*/* CREATE TABLE dirent_types (id INTEGER not NULL, Icon VARCHAR (), name VARCHAR (), PRIMARY KEY (id));
INSERT into Dirent_types VALUES (1, ' folderclosed ', ' Directory ');
INSERT into Dirent_types VALUES (2, ' document ', ' File '); CREATE TABLE directory (ID integer not NULL, parent INTEGER REFERENCES directory (ID), name VARCHAR, icon VARCHAR
(m), type INTEGER REFERENCES dirent_types (id), URL VARCHAR (), PRIMARY KEY (id));
DROP INDEX Directory_idx;
CREATE UNIQUE INDEX directory_idx on directory (parent, name);
CREATE SEQUENCE dirent_id; "CREATE PROCEDURE insert_dir_entry (name VARCHAR, parent INTEGER, type INTEGER) RETURNS (ID integer) BEGIN EXEC SQL when
 EVER SQLERROR ABORT; EXEC SEQUENCE dirent_id.
 NEXT into ID;
 EXEC SQL PREPARE c_insert INSERT into directory (ID, parent, type, name) VALUES (?,?,?,?); EXEC SQL EXECUTEC_insert USING (ID, parent, type, name);
EXEC SQL DROP C_insert;
End ";
Call Insert_dir_entry (' My Computer ', NULL, 1);
Call Insert_dir_entry (' Network neighbourhood ', NULL, 1);
Call Insert_dir_entry (' lucifer.guardian.no ', 2, 1);
Call Insert_dir_entry (' rafael.guardian.no ', 2, 1);
Call Insert_dir_entry (' uriel.guardian.no ', 2, 1);
Call Insert_dir_entry (' Control Panel ', NULL, 1);
Call Insert_dir_entry (' Services ', 6, 1);
Call Insert_dir_entry (' Apache ', 7, 2);
Call Insert_dir_entry (' Solid Server 2.2 ', 7, 2);
 * Function icon ($icon, $name = ', $width = 0, $height = 0) {global $DOCUMENT _root;
 $icon _loc = '/pics/menu ';
 $file = "$DOCUMENT _root$icon_loc/$icon. gif";
 if (! $width | |! $height) {$iconinfo = getimagesize ($file);
 if (! $width) {$width = $iconinfo [0];
 } if (! $height) {$height = $iconinfo [1];
 } printf ('  ', $name?
"Name=\" $name \ "": ", $icon, $width, $height); } function Display_directOry ($parent, $showdepth =0, $ancestors =false) {global $child _nodes, $node _data, $last _child;
 Reset ($child _nodes[$parent]);
 $size = sizeof ($child _nodes[$parent]);
 $lastindex = $size-1;
 if (! $ancestors) {$ancestors = array ();
 } $depth = sizeof ($ancestors); printf (' <div id= "node_%d" class= "Direntry" visibility= "%s" > ", $parent, $showdepth > 0?
 ' Show ': ' Hide '); while (the list ($index, $node) = each ($child _nodes[$parent])} {for ($i = 0; $i < $depth; $i + +) {$up _parent = (int) $node
 _data[$ancestors [$i]][' parent '];
 $last _node_on_generation = $last _child[$up _parent];
 $uptree _node_on_generation = $ancestors [$i];
 if ($last _node_on_generation = = $uptree _node_on_generation) {icon ("blank");
 else {icon ("line");
 } if ($child _nodes[$node]) {//has children, i.e. it is a folder $conn _icon = "plus";
 $expand = true;
 else {$conn _icon = "Join";
 $expand = false;
 } if ($index = = $lastindex) {$conn _icon. = "Bottom"; } elseif ($depth = = 0 && $index = = 0) {$conn _icon. = "Top";
 if ($expand) {printf ("<a href=\" javascript:document.layers[' node_%d '].visibility= ' show ' > ', $node);
 Icon ($conn _icon, "Connimg_$node");
 if ($expand) {print ("</a>");
 $icon = $node _data[$node] [' Icon '];
 if (! $icon) {$type = $node _data[$node] [' type '];
 $icon = $GLOBALS [' dirent_icons '] [$type];
 Icon ($icon, "Nodeimg_$node");
 $name = $node _data[$node] [' name '];
 printf ('? <font size= "%d" >%s</font><br%c> ',-1, $name, 10);
 if ($child _nodes[$node]) {$newdepth = $showdepth;
 if ($newdepth > 0) {$newdepth-;
 } $new _ancestors = $ancestors;
 $new _ancestors[] = $node;
 Display_directory ($node, $newdepth, $new _ancestors);
} print ("</div\n>");
 function Setup_directory ($parent, $maxdepth) {global $dirent _icons, $child _nodes, $node _data, $last _child;
 $dirent _icons = Sql_assoc (' SELECT id,icon from Dirent_types ');
 $query = ' SELECT id,parent,type,icon,name '.
 ' From directory '. ' ORDER BYParent,name ';
 $child _nodes = Array ();
 $node _data = Array ();
 $res = SQL ($query);
 while (list ($id, $parent, $type, $icon, $name) =db_fetch_row ($res)) {$child _nodes[(int) $parent] [] = $id; $node _data[$id] = array (' ID ' => $id, ' parent ' => $parent, ' type ' => $type, ' icon ' => $icon, ' name ' =>
 $NAME);
 $last _child[(int) $parent] = $id; }}?>

I hope this article will help you with your PHP programming.