Get the next and before words from a word - php

Question

I have tb words in a database :
=====================
= id = kata = posisi
=====================
= 1 = you = 1 =
= 2 = should= 2 =
= 3 = eat = 3 9 20 =
etc
Column posisi shows the positions of words in a sentence, that can be has 2 or more position for every word that I separated their position with space in its coloumn. The table comes from indexing process for sentence :
You should eat two bananas before lunch and eat two before your dinner and then consume one banana. i eat banana
I wanna get 5 words before and 5 next words from a keyword.
for example I submit keyword and I will get result :
eat two bananas before lunch and eat two before your dinner
and
eat two before your dinner and then consume one banana. i
here's the code I've tried :
require_once 'connection.php';
function getPosition ($keyword) {
$key = strtolower($keyword);
$query = mysql_query("SELECT * FROM words WHERE kata = '$key' ") or die(mysql_error());
while ($row = mysql_fetch_array($query)) {
$position = $row['posisi'];
}
return $position;
}
$key= 'And';
$and = getPosition($key);
$explode = explode (' ', $and);
foreach ($explode as $data => $datas){
for ($i = 1 ; $i < 6 ;$i++){
$nextdata[$i] = (int)$datas + $i;
$databefore[$i] = (int)$datas - $i;
$queryNext = mysql_query("SELECT kata FROM words WHERE posisi = '$nextdata[$i]' and posisi =$databefore[$i] ") or die(mysql_error());
while ($row = mysql_fetch_array($queryNext)) {
$position = $row['kata'];
}
//print_r($position);
}
}
But it doesn't work, maybe the problem is when it meet the column with has many position, it can't be read it. Please help me. Thank You :)