Recursive sum in query

Question

I have a table with data stored hierarchicaly using adjacency list like in the following example

id     account parent
1      root    null
2      a1      1
3      b1      1
4      a2      2
5      a3      4
6      a4      2
7      b2      3

And a table where I keep values for these accounts

id_account    value
2             10
2             10
4             20
5             30
6             10 

I made a function which returns all child account given a parent account:

function getChildrenAccount($parent_id)
  {
    $query = "SELECT id, account FROM accounts WHERE parent='{$parent_id}' ORDER BY account";
    $result = mysql_query($query) or die(mysql_error());
    while($r[]=mysql_fetch_assoc($result));
    return $r;
  }

What I'm trying to do is a function which returns not only children accounts but also the sum of all values including children of every result. For example

getChildrenAccount(4)

Would return an array with the following syntax

array(1) { 
  [0]=> array(3) { 
     ["id"]=> 5
     ["account"]=> "a3"
     ["sum"]=> 50 //a2 + a3
}

And

getChildrenAccount(2)

array(2) { 
  [0]=> array(3) { 
     ["id"]=> 4
     ["account"]=> "a2"
     ["sum"]=> 70 //a1 + a2 + a3
  [1]=> array(3) { 
     ["id"]=> 6
     ["account"]=> "a4"
     ["sum"]=> 30 //a1 + a4
}

I think I have to use some kind of recursion in my while statement but I'm a little bit confused. Can you help me please?

Thanks

Answer 1

function getChildrenAccount($accountID){

   $query = ' SELECT id,account,sum(value) as `SUM`
    FROM accounts,accountsValues
    WHERE accounts.id = accountsValues.id_accounts
    AND id = $accountID 
    OR id IN (SELECT id FROM accounts where parent = $accountID) ';
....
}

Answer 2

You need to iterate over your result, then for each id call getChildrenAccount for its parent id.

Answer 3

I found a function which gets results as needed without recursive queries.

$nodeList = array();
$tree     = array();
$query = mysql_query("SELECT A.guid, A.name, A.parent_guid, SUM( S.value_num ) /100 AS suma FROM accounts AS A
    LEFT JOIN splits AS S ON S.account_guid = A.guid GROUP BY A.guid ORDER BY A.name");
while($row = mysql_fetch_assoc($query))
  $nodeList[$row['guid']] = array_merge($row, array('children' => array()));
mysql_free_result($query);

foreach ($nodeList as $nodeId => &$node) {
  if (!$node['parent_guid'] || !array_key_exists($node['parent_guid'], $nodeList))
    $tree[] = &$node;
  else 
    $nodeList[$node['parent_guid']]['children'][] = &$node;
}
unset($node);
unset($nodeList);