php recursive function for genealogical tree

Question

I have in database people with relation to parents and I need to create recursive function which return array with genealogical tree. Database example:

NUMBER;NAME;FATHER;MOTHER
001;Name1;002;005
002;Name2;007;018
003;Name3;018;025
005;Name5;006;019
023;Name23;019;045
018;Name18;062;097
007;Name7;;-
...

I prepared two functions - first for man detail and second recursive for search ancestors.

I need this result:

$out[0][0] // first person
$out[1][0] // mother of first person
$out[1][1] // father of first person
$out[2][0] // grandmother of first person (mother side)
$out[2][1] // grandfather of first person (mother side)
$out[2][2] // grandmother of first person (father side)
$out[2][3] // grandmother of first person (father side)
...

next generation have 8 items, next 16 items, ... Maximum is 6 generations back.

I prepared two functions - first for man detail and second recursive for tree building. In second function

define("MAX_GEN",5);

function detail($number) {
    $d = mysql_query("select * from table where number = '$number'");
    if(mysql_num_rows($d) == 0) {
        $p[name] = "N/A";
        $p[number] = "N/A";
        $p[m_number] = "N/A";
        $p[f_number] = "N/A";
    }
    else $p = mysql_fetch_assoc($d);
    return $p;
}

function gen($number, $generation = 0, $out) {

    if ($generation >= MAX_GEN) {
        return false;
    }

    $record = detail($number);

    if ($generation == 0) $out[0][] = $record; // first man

    $generation++; // next generation

    if (!$out[$generation] && ($generation != MAX_GEN)) $out[$generation] = array();

    $x_mother = gen($record[m_number], $generation ); // continue with mother
    $x_father = gen($record[f_number], $generation ); // continue with father

    if ($out[$generation]) {
        $out[$generation][] = $x_mother;
        $out[$generation][] = $x_father;
    }
    return $out;
}

But in second function is problem - I don't know how pass array with results to next and next generation. It's still return one element or (after few attempts) it returns array which I want but with inserted arrays between generations and result is unusable. Can anyone help me please?

Example of result which I wand is here: http://www.foxterrier.cz/_TM_importy/example.php

Answer 1

This is mostly a comment - but its a bit long.

You are very constrained by both your database design and your desire output format. Even without going to the cost/complexity of a graph database there are lots of ways of representing hierarchical data in a relational database.

Your output format list each generation but does not maintain the mother-father association, and does not lend itself to mapping out sideways or forwards - only backwards.

Your implementation requires that you run 2^N (where N is the number of generations) queries, each time making a round triup from PHP code back to the DBMS. Performance will suck.

As a minimum you should consider resolving a generation at a time:

  $ref=mysql_real_escape_string(session_id());
  mysql_query(
    "INSERT INTO results (generation, number, ref) VALUES (0, $start_number, '$ref')"
  );

  for ($x=1; $x<=max_gens; $x++) {
    mysql_query(
  "INSERT INTO results (generation, number, ref)
  SELECT $x, father, '$ref'
  FROM yourtable yt JOIN results rs ON yt.number=results.number 
  WHERE rs.generation=$x-1
  UNION 
  SELECT $x, mother, '$ref'
  FROM yourtable yt JOIN results rs ON yt.number=results.number 
  WHERE rs.generation=$x-1"
     );
  }

(but with more error checking - and remember to clear out the data later)

Answer 2

Updated essam eg's solution - now fully working:
- removed char $ before MAX_GET in first for cycle
- removed $generation in cycle ($i enough)
- add call detail in ($out[$i][] = $record[m_number]; -> $out[$i][] = detail($record[m_number]);)
- modify adding father to array (mother was twiced and father was missing)

define("MAX_GEN",5);

function detail($number) {
    $d = mysql_query("select * from table where number = '$number'");
    if(mysql_num_rows($d) == 0) {
        $p[name] = "N/A";
        $p[number] = "N/A";
        $p[m_number] = "N/A";
        $p[f_number] = "N/A";
    }
    else $p = mysql_fetch_assoc($d);
    return $p;
}

$main_person_number=001;//number in database
$out[0][] =detail($number);// main person


for($i=1;$i<MAX_GEN;$i++){
  $parent=$i-1;
  for($j=0;$j<pow(2,$parent);$j++){
      $record = detail($out[$parent][$j]['number']);
  $out[$i][] = detail($record[m_number]);
  $out[$i][] = detail($record[f_number]);
    }
}

Answer 3

I prefer to use iteration to create $out array

instead of gen function

the iteration count increases 1 -> 2 -> 4 ->8

= 2 ^($generation-1)

$parent=$generation-1;
      for($j=0;$j<pow(2,$parent);$j++){

the full code

define("MAX_GEN",5);

function detail($number) {
    $d = mysql_query("select * from table where number = '$number'");
    if(mysql_num_rows($d) == 0) {
        $p[name] = "N/A";
        $p[number] = "N/A";
        $p[m_number] = "N/A";
        $p[f_number] = "N/A";
    }
    else $p = mysql_fetch_assoc($d);
    return $p;
}

$main_person_number=001;//number in database
$generation = 0;
$out[0][] =detail($number);// main person
$generation++; // next generation

for($i=1;$i<$MAX_GEN;$i++){
  $parent=$generation-1;
  for($j=0;$j<pow(2,$parent);$j++){
      $record = detail($out[$parent][$j]['number']);
  $out[$generation][] =$record[m_number];
  $out[$generation][] =$record[m_number];
    }
   $generation++;   
}