Packageid  Scanid  dispatchid  timestamp   status
   p1         s1       null        t1        'in'
   p2         s1       xxx         t2        'in'
   p1         s2       yyy         t3        'pkin'
   p1         s3       sss         t4        'iwi'
   p1         s4       eee         t5        'lhp'
   p2         s2       uuuu        t6        'uio'
   p2         s3       null        t7        'jsk'

Packageid   Latest-Scanid   First-Dispatch-time  Last-Dispatch-time   latest-status

 p1            s4                 t3                 t5                 'lhp'
 p2            s3                 t2                 t6                 'jsk'