Making an array producing parents and children of records

I cannot figure out how to make a parent, child (by an id) that be put into an new array from an array (loaded by a database).

I need it to be like this:

+- Parent - ID: 4
|
+---- Child record  
+---- Child record  <-- these children have a parent_id of 4
+---- Child record
|
+- Parent - ID: 5
|
+---- Child record 
+---- Child record
+---- Child record
+---- Child record  <-- these children have a parent_id of 5
+---- Child record 
|
+- Parent - ID: 7
|
+---- Child record  
+---- Child record  <--开发者_如何学C these children have a parent_id of 7
+---- Child record

And so on, the record loaded from the database looks like this:

Array
(
    [0] => Array
        (
            [id] => 1
            [info] => this is a child, since sub is 1 and parent_id contains a number
            [sub] => 1
            [parent_id] => 4
        )

    [1] => Array
        (
            [id] => 2
            [info] => this is a parent, since sub is 0 and parent_id does not contain a number
            [sub] => 0
            [parent_id] => 
        )

    [2] => Array
        (
            [id] => 1
            [info] => this is a child, since sub is 1 and parent_id contains a number
            [sub] => 1
            [parent_id] => 4
        )

.... more records

The SQL is ordered in ascending mode by the row id, the new array containing parents and child of records what it's basically for.

foreach($dbArray as $row)
{
    if($row['parent_id'] != "")
    {
        $parentArray[$row['parent_id']][]['child'] = $row['info'];

    }
    else
    {
        $parentArray[$row['id']]['parent'] = $row['info'];
    }

}

this is where the parent id is the key for the array of child info The resulting array would look something like this

Array(
/*parent id*/
    [0]=>Array(
       [parent] => //whatever info
       [0] => Array(
               [child]=> //whatever child info
                   )

           )
      )