title: Select rows from multiple tables with common fields in sqlite
body: <p>I have a table as follows:</p>
  
  <p>create table table1(id integer,firstname text,lastname text);</p>
  
  <p><h3>id firstname lastname</h3>====================<br/>
  1 ben   taylor<br/>
  2 rob   taylor<br/>
  3 rob   smith<br/>
  4 rob   zombie<br/>
  5 peter smith<br/>
  6 ben smith<br/>
  7 peter   taylor<br/></p>
  
  <p>Now I have another table create table table2(id integer,position integer); 
  <h3>id position</h3>===========<br/>
  1 5<br/>
  1 9<br/>
  2 6<br/>
  3 7<br/>
  6 2<br/></p>
  
  <p>I want to select rows with a lastname , where the lastname must be shared by ben and rob and firstnames must be ben and rob.<br/>
  Now I also want the position of ben to be one lesser than that of rob, hence the result would be : <br/>
  <h3>id firstname lastname position</h3>===========================<br/>
  1 ben   taylor 5<br/>
  2 rob   taylor 6<br/></p>
  
  <p>What should the sql query be ?</p>