SEARCH PHP MYSQL QUERY - php

Question

I am trying to make a search program. I have three tables: postivewords, negativewords and recommendationwords. These tables consist only of word_id then the word. How I do it in a query? This is what I have so far. Please correct me if I am wrong.
if(isset($_POST['searchword']))
{
$word = $_POST['search'];
$search1= mysql_fetch_array(mysql_query("SELECT * FROM positivethesaurus where word like '%$word%'"));
$search2= mysql_fetch_array(mysql_query("SELECT * FROM negativethesaurus where word like '%$word%'"));
$search3= mysql_fetch_array(mysql_query("SELECT * FROM recommendationthesaurus where word like '%$word%'"));
}

Answer 1

select * from negativethesaurus, positivethesaurus,recomendationthesaurus where negativethesaurus.word like '%"word%' or positivethesaurus.word like '%word%' or recomendationthesaurus.word like '%word%';
This may be not the fastest way (you would use indexes and freetext) but it will be down on only one query.
Oh yes, that been said this query is vulnerable to sql injection attacks.

Answer 2

also do mysql_escape_string to avoid sql injection
$word = $_POST['search'];
$word = mysql_escape_string($word);

Answer 3

$query = SELECT positivethesaurus .*,negativethesaurus.*,recommendationthesaurus.* FROM positivethesaurus,negativethesaurus,recommendationthesaurus where positivethesaurus.word like '%$word%' OR negativethesaurus.word like '%$word%' OR recommendationthesaurus.word like '%$word%'";
UPDATES
if you want to check if results not found then do it like this
<?php
$query = mysql_query("Your Query Here");
$rowCount = mysql_num_rows($query);
if($rowCount>0) {
// DO YOur STUFF IF RESULTS FOUND
} else {
echo "No Results Found";
}
?>
Please not that mysql_* function should not be used
Hope this works. Not Tested though. Let me know if you find any problem

Answer 4

1) Select the respected column instead of select * from
2) avoid sql injection