title: if with isset for $GET
body: <p>Here is the extract of PHP code that is working as expected.</p>
  
  <p>But I want to modify the sql query.
  The inner join b,c,d,e should not be part of the query unless the respective first,second,third variables are set.</p>
  
  <pre><code>$word_first=$_GET["first"];
  $word_second=$_GET["second"];
  $word_third=$_GET["third"];
  $word_forth=$_GET["forth"];
  $word_fifth=$_GET["fifth"];
  $word_sixth=$_GET["sixth"];
  $word_seventh=$_GET["seventh"];
  $word_eighth=$_GET["eighth"];
  
  
  $query="select id, word from toprint as a
  inner join syl as b on b.word_id = a.id and b.char_id = '1' AND b.mychar LIKE '%".$word_first. "%' 
  inner join syl as c on c.word_id = a.id and c.char_id = '2' AND c.mychar LIKE '%".$word_second. "%' 
  inner join syl as d on d.word_id = a.id and d.char_id = '3' AND d.mychar LIKE '%".$word_third. "%' 
  inner join syl as e on e.word_id = a.id and e.char_id = '4' AND e.mychar LIKE '%".$word_forth. "%' 
  inner join syl as f on f.word_id = a.id and f.char_id = '5' AND f.mychar LIKE '%".$word_fifth. "%' 
  inner join syl as g on g.word_id = a.id and g.char_id = '6' AND g.mychar LIKE '%".$word_sixth. "%' 
  inner join syl as h on h.word_id = a.id and h.char_id = '7' AND h.mychar LIKE '%".$word_seventh. "%'
  inner join syl as i on i.word_id = a.id and i.char_id = '8' AND i.mychar LIKE '%".$word_eighth. "%'
  limit 2000";
  </code></pre>