PHP function does not return a value

Question

I have a recursive function that returns a value.

    public function getparent ($user)
    {
        $referrer=''; $pos=0;$this->setFieldNames();
        $result=mysql_query("select * FROM ". $this->dbtablename ." WHERE ".$this->id_field . " = '$user'", $this->dbConnectionID);
        while($row=mysql_fetch_array($result, MYSQL_ASSOC))
        {
            $referrer=$row['referrer'];
            $export=array();
            foreach($this->tablefields as $val){
                $export[$val] = $row[$val];
            }
        }
        if($referrer != "0" && $referrer != "")
        {
            $result2=mysql_query("select * from " . $this->dbtablename . " where " . $this->id_field . " ='$referrer'", $this->dbConnectionID);
            while($row2=mysql_fetch_array($result2, MYSQL_ASSOC))
            {
                $export=array();
                foreach($this->tablefields as $val){
                    $export[$val] = $row2[$val];
                }
            }
        }

        $result2=mysql_query("select * from " . $this->dbtablename . " where " . $this->parent_id_field . " ='$referrer' order by id asc", $this->dbConnectionID);
        while($row2=mysql_fetch_array($result2, MYSQL_ASSOC))
        {
            $usernames[]=$row2['username'];
        }
        $pos=array_search($user, $usernames);
        if( $referrer == '0' || $pos >=1 )
        {echo 'xxxxxxx';
            return $export;
        }
        else
        {
            $this->getparent($referrer);
        }
    }

It seems that when the $referrer is zero it doesnt return any value, yet it echoes 'xxxxxxx'. What can the problem be!?

Rudu · Accepted Answer · 2010-09-15 14:35:09Z

2

There's a problem with:

    while($row=mysql_fetch_array($result, MYSQL_ASSOC))
    {
        $referrer=$row['referrer'];
        $export=array();
        foreach($this->tablefields as $val){
            $export[$val] = $row[$val];
        }
    }

You're replacing your export array on every iteration - is that your intent? The data is being thrown away for all but the last row. Then you do it again in this block:

    if($referrer != "0" && $referrer != "")
    {
        $result2=mysql_query("select * from " . $this->dbtablename . " where " . $this->id_field . " ='$referrer'", $this->dbConnectionID);
        while($row2=mysql_fetch_array($result2, MYSQL_ASSOC))
        {
            $export=array();
            foreach($this->tablefields as $val){
                $export[$val] = $row2[$val];
            }
        }
    }

Where you're (a) only getting the last row of data and (b) overriding the data from the first block (perhaps that latter is desired).

And finally if you ever hit this block (referrer isn't zero the first time through your code):

    else
    {
        $this->getparent($referrer);
    }

You never reutrn a value from the recursive call, it should be:

    else
    {
        return $this->getparent($referrer);
    }

Which I suspect is the actual issue. But I've got to question whether this recursive approach is best, rather than an iterative one.

edited Sep 15, 2010 at 14:35

answered Sep 15, 2010 at 14:28

Rudu

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1 Comment

Ogugua Belonwu Over a year ago

The $export array i overwrite is actually intentional, though each while loop returns only one row. Your last suggestion did the magic, but i was thinking its nt compulsory it must return a value at that point. Pls kindly explain the iterative approach to me.

Marouane Gazanayi · Accepted Answer · 2010-09-15 11:07:05Z

0

Try to declare $export before the while loop

answered Sep 15, 2010 at 11:07

Marouane Gazanayi

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1 Comment

Ogugua Belonwu Over a year ago

i just did that, i removed the declaration from the while loops and put on top, yet it didnt work, i even tried to return a static string yet it didnt return anything.

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