php从数据库查询结果生成树形列表的方法

本文实例讲述了php从数据库查询结果生成树形列表的方法。分享给大家供大家参考。具体分析如下：

本代码可以从数据库读取数据生成一个类似于windows的资源管理器的树形列表

    <?php
    /* Here are the database definitions (for Solid) that i use in this code.
     * It should not be hard to adapt it to another database.
     */
    /*
    CREATE TABLE dirent_types (
     id INTEGER NOT NULL,
     icon VARCHAR(50),
     name VARCHAR(50),
     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(200),
     icon VARCHAR(50),
     type INTEGER REFERENCES dirent_types(id),
     url VARCHAR(200),
     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 WHENEVER SQLERROR ABORT;
     EXEC SEQUENCE dirent_id.NEXT INTO id;
     EXEC SQL PREPARE c_insert
     INSERT INTO directory
     (id, parent, type, name)
     VALUES(?, ?, ?, ?);
     EXEC SQL EXECUTE c_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( '<img%s border=0 align=top src="/pics/menu/%s.gif" '.
     'width="%d" height="%d">', $name ? " name=\"$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, $showdepth > 0 ? 'show' : 'hide');
     while (list($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 BY parent,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;
     }
    }
    ?>

希望本文所述对大家的php程序设计有所帮助。