text: select
      t1.col2,
      t2.col2,
      t3.col3,
      t4.col2 
  from
      table1 t1,
      table2 t2,
      table3 t3,
      table4 t4  
  where
      t1.col1=t2.col1 
  	and t2.col2=t1.col2 
      and t2.col2=t4.col2 
      and t2.col1=t4.col1  
  group by
      t3.col1,
      t3.col2 
  order by
      t4.col2;