title: How to select from query string in oracle
body: <p>Lets assume, I have a string that holds a query string. </p>
  
  <p>How can I select the rows from that query string in oracle ?</p>
  
  <p>I tried <code>execute immediate</code> but it returns nothing.</p>
  
  <pre><code>declare 
      hello varchar(30000);
  begin
      hello:='select * from test_table';
      execute immediate hello;    
  end;
  </code></pre>