function get_search_sql($select_columns, $table, $search_fields, $search_terms, $group_by="", $limit="")
{
	$search = array_combine($search_fields, $search_terms);
 
	$count = 0;
	foreach($search as $field => $term) {
		
		if (trim($term) == "")
			continue;
	
		if (!get_magic_quotes_gpc()) {
			$term = addslashes($term);
		}
		
		if (!$count) {
			$sql_fields = "";
			$sql_fields_replace = "";
			
		} else {
			$sql_fields.= ",";
			$sql_fields_replace.= ",";
			
		}
		
		$sql_fields.= $field;
		
		$terms = explode(" ", $term);
		
		$tmp_fields_replace = "LOWER($field)";
 
		foreach($terms as $term) {
			if ($count)
				$sql_search.= "OR ";
				
			$term = trim(strtolower($term));
				
			$tmp_fields_replace = "REPLACE($tmp_fields_replace,'$term','')";
			$sql_search.= "LOWER($field) LIKE '%$term%' ";
			
			$count++;
		}
		
		$sql_fields_replace.= $tmp_fields_replace;
	}
	
	if (trim($group_by) != "")
		$group_by = "GROUP BY $group_by";
	if (trim($limit) != "")
		$limit = "LIMIT $limit";
	
	return "SELECT $select_columns, ( LENGTH(CONCAT($sql_fields)) - LENGTH(CONCAT($sql_fields_replace)) ) / LENGTH(CONCAT($sql_fields)) AS relevancy FROM $table WHERE $sql_search $group_by ORDER BY relevancy DESC $limit";
}

SELECT id, ( LENGTH(CONCAT(col1,col2)) - LENGTH(CONCAT(REPLACE(REPLACE(LOWER(col1),'col1word1',''),'col1word2',''),REPLACE(LOWER(col2),'col2word1',''))) ) / LENGTH(CONCAT(col1,col2)) AS relevancy 
FROM TABLE 
WHERE LOWER(col1) LIKE '%col1word1%' OR LOWER(col1) LIKE '%col1word2%' OR LOWER(col2) LIKE '%col2word1%' 
ORDER BY relevancy DESC