Help stop re-replaceing a word

[newprogram]

Ok I'm trying to make word replace but I'm have some problems ,  first I have in my database row "words" have the words it look for to replace row "wordsys" have the replacement word

the problem I'm have is let say the text I want to replace is "My friend is in here house" and row "words" has "My, In , here" in it and the replacement words are in wordsys has "In for My" "We for In" and "gone for here"

 

so first it going to replace "My" with "In" that good ,but then it going back and replacing "In" the we just replaced with "We" and so forth who do I stop it from re-replace a word that it already replace.

<?php

//connect to database

 

$textw = "My friend is in here house";

//load all replacements

$result = mysql_query("SELECT * FROM data");

//replace all words

$words = array();

$replacewords =array();

while ($row = mysql_fetch_assoc($result)) {

    $words[] = $row['words'];

    $replacewords[] = $row['wordsys'];

}

$text = str_replace($words,$replacewords,$textw);

echo $text;

?>

 

 

Thank you for your help

[PFMaBiSmAd]

I know what you want, but what is the correct resulting $text that your example should produce?

[newprogram]

it should produce "In friend is We gone house"

[PFMaBiSmAd]

One possible way -

<?php
//connect to database

$textw = "My friend is in here house";

// determine which words to retrieve (save some processing and query time)
$parts = explode(' ',$textw); // $parts is also used later in the replace operation
$find = implode("','",$parts);

//load just the replacements
$query = "SELECT * FROM data WHERE words IN ('$find')";
$result = mysql_query($query);

//get replacement words
$replacewords =array();
while ($row = mysql_fetch_assoc($result)) {
    $replacewords[strtolower($row['words'])] = $row['wordsys']; // key is the original word, value is the replacement
}
foreach($parts as $key=>$part){
if(isset($replacewords[strtolower($part)])){
	$parts[$key] = $replacewords[strtolower($part)];
}
}
$text = implode(' ',$parts);
echo $text;
?>

[newprogram]

this works great thank you