本文实例讲述了php+mysql查询实现无限下级分类树输出。分享给大家供大家参考，具体如下：
这里介绍的php结合mysql查询无限下级树输出，其实就是无限分类。给各位整理了几个php无限分类的例子.
树输出:
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function get_array($user_id,$top=0){global $mysql,$_G; $sql = "select user_id as name from `{spreads_users}` where p1.spreads_userid='{$user_id}'";$rows= $mysql->db_fetch_arrays($sql); if($top==1){ $arr[0]['name']=$user_id; $arr[0]['children']=array(); } $top=$top+1;foreach ($rows as $key=>$value) { $r = get_array($value['name']); //调用函数，传入参数，继续查询下级 $arr[0]['children'][$key]['name']= $value['username']; //组合数组 if(is_array($r)){ $arr[0]['children'][$key]['children']= $r[0]['children']; } $i++; } return $arr; }$list = get_array("1000",1); //调用函数1000是顶级IDecho 'var data='.json_encode($list); |
这个是输出 Array 然后转让为 json
例子:
表结构:id字段为分类标识，name字段为分类名,father_id字段为所属父分类的id,path字段为分类路径,储存该分类祖先的集合,isdir判断是否是目录,1为是,0为否.
显示函数:
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//$count为分类等级sort_list($str,$fatherid,$count){$rs = $this->sql->re_datas("select * from sort where father_id = fatherid");$num = $this->sql->sql_numrows();$i=0;$n = 1;while(isset($rs[$i])){$name = "";for($n = 1 ; $n < $count ; $n ){$name.="│ ";}if($i 1==$num){$name.="└─".$rs[$i][name];}else{$name.="├─".$rs[$i][name];}if($rs[$i][isdir]){$str.="<span style='color:#CCCCCC'>".$name."</span>";}else{$str.=$name";}$temp = $count 1;$str = $this->sort_list($str,$rs[$i][id],$temp);$i ;}return $str;} |
其中$this->sql对象为sql操作类对象,re_datas()函数返回查到的数组,sql_numrows()函数返回查询到的数目.
调用方法:
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$sort_list = sort_list($sort_list,0,1); |
例子:
表:category
id int 主键,自增
name varchar 分类名称
pid int 父类id，默认0
顶级分类的 pid 默认就是0了,当我们想取出某个分类的子分类树的时候,基本思路就是递归,当然,出于效率问题不建议每次递归都查询数据库,通常的做法是先讲所有分类取出来,保存到PHP数组里,再进行处理,最后还可以将结果缓存起来以提高下次请求的效率.
先来构建一个原始数组,这个直接从数据库中拉出来就行:
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$categories = array( array('id'=>1,'name'=>'电脑','pid'=>0), array('id'=>2,'name'=>'手机','pid'=>0), array('id'=>3,'name'=>'笔记本','pid'=>1), array('id'=>4,'name'=>'台式机','pid'=>1), array('id'=>5,'name'=>'智能机','pid'=>2), array('id'=>6,'name'=>'功能机','pid'=>2), array('id'=>7,'name'=>'超级本','pid'=>3), array('id'=>8,'name'=>'游戏本','pid'=>3),); |
目标是将它转化为下面这种结构:
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电脑—笔记本——-超级本——-游戏本—台式机手机—智能机—功能机 |
用数组来表示的话,可以增加一个 children 键来存储它的子分类:
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array( //1对应id，方便直接读取 1 => array( 'id'=>1, 'name'=>'电脑', 'pid'=>0, children=>array( &array( 'id'=>3, 'name'=>'笔记本', 'pid'=>1, 'children'=>array( //此处省略 ) ), &array( 'id'=>4, 'name'=>'台式机', 'pid'=>1, 'children'=>array( //此处省略 ) ), ) ), //其他分类省略) |
处理过程:
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$tree = array();//第一步，将分类id作为数组key,并创建children单元foreach($categories as $category){ $tree[$category['id']] = $category; $tree[$category['id']]['children'] = array();}//第二部，利用引用，将每个分类添加到父类children数组中，这样一次遍历即可形成树形结构。foreach ($tree as $k=>$item) { if ($item['pid'] != 0) { $tree[$item['pid']]['children'][] = &$tree[$k]; }} |
print_r($tree);打印结果如下:
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Array( [1] => Array ( [id] => 1 [name] => 电脑 [pid] => 0 [children] => Array ( [0] => Array ( [id] => 3 [name] => 笔记本 [pid] => 1 [children] => Array ( [0] => Array ( [id] => 7 [name] => 超级本 [pid] => 3 [children] => Array ( ) ) [1] => Array ( [id] => 8 [name] => 游戏本 [pid] => 3 [children] => Array ( ) ) ) ) [1] => Array ( [id] => 4 [name] => 台式机 [pid] => 1 [children] => Array ( ) ) ) ) [2] => Array ( [id] => 2 [name] => 手机 [pid] => 0 [children] => Array ( [0] => Array ( [id] => 5 [name] => 智能机 [pid] => 2 [children] => Array ( ) ) [1] => Array ( [id] => 6 [name] => 功能机 [pid] => 2 [children] => Array ( ) ) ) ) [3] => Array ( [id] => 3 [name] => 笔记本 [pid] => 1 [children] => Array ( [0] => Array ( [id] => 7 [name] => 超级本 [pid] => 3 [children] => Array ( ) ) [1] => Array ( [id] => 8 [name] => 游戏本 [pid] => 3 [children] => Array ( ) ) ) ) [4] => Array ( [id] => 4 [name] => 台式机 [pid] => 1 [children] => Array ( ) ) [5] => Array ( [id] => 5 [name] => 智能机 [pid] => 2 [children] => Array ( ) ) [6] => Array ( [id] => 6 [name] => 功能机 [pid] => 2 [children] => Array ( ) ) [7] => Array ( [id] => 7 [name] => 超级本 [pid] => 3 [children] => Array ( ) ) [8] => Array ( [id] => 8 [name] => 游戏本 [pid] => 3 [children] => Array ( ) )) |
优点:关系清楚,修改上下级关系简单.
缺点:使用PHP处理,如果分类数量庞大,效率也会降低.
希望本文所述对大家PHP程序设计有所帮助。
