Google like search engine with php

What is the proper way to build a dynamic subquery ? I want to allow the user to use AND, OR, and NOT in his/her query like $query = "Hola AND Adios, OR Goodbye, NOT hello" or.. WHERE (greeting LIKE %Hola% AND greeting LIKE %Adios%) OR (greeting LIKE %Goodbye%) AND (greeting NOT LIKE %hello%) I am a bit new at this so any help would be appretiated :) My Guess: AND,OR,NOT,'+', and '-' would be extracted from query and put into an array. So all the operators become $wordOperator[ ] where: 'hola' : $wordOperator[0] = "AND" 'Adios': $wordOperator[1] = "AND" 'greeting' : $wordOperator[2] = "OR" 'hello' : $wordOperator[3] = "NOT" // My script in its current state $query = "Hola Adios" //taken from a GET request //parse by a space $searchwords = explode(" ",$query); $x = 1; $operator = "AND"; $not_search_word = array('if', 'for', 'in', 'on','and','with'); //taken from a GET request $searchwords = explode(" ",$query); foreach ($searchwords as $word) { if (!in_array($word,$not_search_word)){ //relevant search term only //if we are on the first word...format subquery like this if ($x == 1){

         $sql .= ' AND(media.'.$language.' Like "%'.$word.'%"';
         $sql .= ' OR artist.'.$language.' Like "%'.$word.'%"';
         $sql .= ' OR artist.name Like "%'.$word.'%")';
         $x++ ;

//formatting for everything past 1st word

    }else{

         $sql .= ' '.$operator.'(media.'.$language.' Like "%'.$word.'%"';
         $sql .= ' OR artist.'.$language.' Like "%'.$word.'%"';
         $sql .= ' OR artist.name Like "%'.$word.'%")';

}

    }

} $sql .= ' ORDER BY artist.name ASC,'; $sql .= ' media.'.$language.' ASC LIMIT 0,60';