title: Convert String into MySQL Query
body: <p>I have this string in PHP:</p>
  
  <pre><code>$str = 1,3,6,5 
  </code></pre>
  
  <p>These numbers can change and the length of the set can change to more or less than four. I want to convert to a MySQL query like this in PHP:</p>
  
  <pre><code>$qry = mysql_query("SELECT * FROM tbl WHERE id = 1 or id = 3 or id = 6 or id = 5")
  </code></pre>
  
  <p>It should be easy, but I don't know how to do it.</p>
  
  <p>I will be grateful for any help.</p>