select
   s.Key
   v1.AverageTimeSpent,
   v1.NumberOfClicks,
   v2.Country
   v3.Purchase as Target
from vw_TrainSample s
left join vw_BehaviourFeatures v1 on v1.Key = s.Key
left join vw_ProfileFeatures v2 on v2.Key = s.Key
left join vw_TargetFeatures v3 on v3.Key = s.Key