i would like the first flight into houston from dallas on march first and the last flight from houston to dallas on march first 
return flights ;return #1 from  dallas  ;return #2 to houston ;return #3 on  march first  ;return first  #4 ;return #1 from  houston ;return #6 to dallas  ;return #7 on  march first  ;return last #8 ;return #5 ,  #9
['select', 'filter', 'filter', 'filter', 'aggregate', 'filter', 'filter', 'filter', 'aggregate', 'union']