php - Copy tree structure recursive - Adjacency List Model -

i try copy tree structure 1 database table another. structure adjacency list model. looks like:

id|parent_id|position 1|0|1 2|1|1 3|1|2 4|0|2 5|4|1  

it necessary id's regenerated (autoinc) in other table! have following functions:

/**  * copy single node , return new id  */ public function copynode($sn_data){     $this->db2->insert('items_configurations', $sn_data);     return $this->db2->insert_id(); }  /**  * return list of child nodes assoziative array  * given parent  */ public function childlist($parent_id){     $tmp  = 'select parent_id,item_id,template_id,position items_templates parent_id='.$parent_id;     $tmp .= ' order position';     $query=$this->db2->query($tmp);     return $query->result_array(); }  /**  * copy whole tree structure through recursive function  */ public function copytree($node_data,$given_parent){     $new_parent = $this->copynode($node_data);     $new_data   = $this->childlist($node_data['id']);     if(is_array($new_data)){         foreach($new_data $new_node_data) :             $new_node_data['parent_id'] = $given_parent;             $new_node_data['configuration_id'] = $node_data['configuration_id'];             $this->copytree($new_node_data,$new_parent);         endforeach;     } }   /**  * first call of function example:  */     $this->copytree(array('parent_id' => 0,'item_id' => 40,'template_id' => 6,'position' => 1),0); 

i want recursive, copies first 2 lines. mistake?

1.you must use current node id parent_id when traversing recursively. , using it's parent_id in childlist:

parent_id='.$parent_id; 

must parent_id='.$id;

you getting peers of node rather, it's children.

2.also suspicious marked line:

if(is_array($new_data)){     foreach($new_data $new_node_data) :         $new_node_data['parent_id'] = $new_parent;//<--         $this->copytree($new_node_data);     endforeach; } 

because have new parent_id , using old table in childlist function. check, whether parameter correct.