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Share a PHP code to implement infinite classification program_PHP tutorial
- WBOYOriginal
- 2016-07-13 10:44:33748browse
Infinite classification is a problem encountered in all program development. Now I will introduce an infinite classification program implemented by php+mysql. Friends in need can refer to it.
Let me show you my database structure: The name of the database is: fa_category
| Field | Type | Comment |
| cid | int(11) | 分类id |
| catename | varchar(255) | 分类名字 |
| catetype | int(1) | 分类类型，1为单页面，2为普通分类 |
| catdir | varchar(255) | 英文目录 |
| display | int(1) | 1为显示，2为不显示 |
| keywords | varchar(255) | 栏目关键字 |
| description | text | 栏目描述 |
| ctime | int(11) | 创建时间 |
| parentid | int(11) | 父节点id，最高节点父节点为0 |
We use a parentid field to record the id of the parent node. If parentid is 0, it is root. Without further ado, let’s see how to write the code. The function we want to achieve is as shown in the picture:
How to display it like this? I have been thinking about this question for a long time. Let’s take a look at this SQL statement first,
| The code is as follows | Copy code |
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SELECT c.cat_id, c.cat_name, c.measure_unit, c.parent_id, c.is_show, c.show_in_nav, c.grade ,c.sort_order, COUNT( s.cat_id ) AS has_children |
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Use a left join to connect a table and return a field has_children. This field records how many child nodes there are.
Let’s take a look at the code,
| 代码如下 | 复制代码 |
| public function getCategory($catid=0,$re_type = true,$selected=0) { $db = new Public_DataBase(); $sql = 'select c.cid,c.catename,c.catetype,c.ctime,c.parentid,count(s.cid) as has_children from '. __MYSQL_PRE.'category as c left join '. __MYSQL_PRE.'category as s on s.parentid=c.cid group by c.cid order by c.parentid asc'; $res = $db->selectTable($sql); $cateInfo = self::getChildTree($catid,$res); if($re_type==true) { $select = ''; foreach($cateInfo as $val) { $select .= ' $select .= ($selected == $val['cid']) ? "selected='ture'" : ''; $select .= '>'; if($val['level']>0) { $select .= str_repeat(' ', $val['level'] * 4); } $select .= htmlspecialchars(addslashes($val['catename']), ENT_QUOTES) . ''; } return $select; } else { foreach($cateInfo as $key=>$val) { if($val['level']>0) { $cateInfo[$key]['catename'] = "|".str_repeat(' ', $val['level'] * 8)."└─".$val['catename']; } } return $cateInfo; } } /** * 通过父ID递归得到所有子节点树 * @param int $catid 上级分类 * @param array $arr 含有所有分类的数组 * @return array */ public function getChildTree($catid,$arr) { $level = $last_cat_id = 0; while (!empty($arr)) { foreach($arr as $key=>$value) { $cid = $value['cid']; if ($level == 0 && $last_cat_id == 0) { if ($value['parentid'] > 0) { break; } $options[$cid] = $value; $options[$cid]['level'] = $level; $options[$cid]['id'] = $cid; $options[$cid]['name'] = $value['catename']; unset($arr[$key]); if ($value['has_children'] == 0) { continue; } $last_cat_id = $cid; $cat_id_array = array($cid); $level_array[$last_cat_id] = ++$level; continue; } if ($value['parentid'] == $last_cat_id) { $options[$cid] = $value; $options[$cid]['level'] = $level; $options[$cid]['id'] = $cid; $options[$cid]['name'] = $value['catename']; unset($arr[$key]); if ($value['has_children'] > 0) { if (end($cat_id_array) != $last_cat_id) { $cat_id_array[] = $last_cat_id; } $last_cat_id = $cid; $cat_id_array[] = $cid; $level_array[$last_cat_id] = ++$level; } } elseif ($value['parentid'] > $last_cat_id) { break; } } $count = count($cat_id_array); if ($count > 1) { $last_cat_id = array_pop($cat_id_array); } elseif ($count == 1) { if ($last_cat_id != end($cat_id_array)) { $last_cat_id = end($cat_id_array); } else { $level = 0; $last_cat_id = 0; $cat_id_array = array(); continue; } } if ($last_cat_id && isset($level_array[$last_cat_id])) { $level = $level_array[$last_cat_id]; } else { $level = 0; } } return $options; |
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}Use a smarty loop to display it. The effect is the same as the picture above! If you have any questions, please leave me a message.