Saturday, October 8, 2016

Get Top N Records per Group

One of the most asked query in the interview,
      how to get top N record in hte each group
      get 15th largest records from DB with out using limit

you can solve above problem statement using rank concept

create a new column in table it will rank your records , by using this rank you can resolve above problem






query and sample dataset  you can get it from the aboe screenshot . and of course result set as well.

basic idea is , creare a session varibale which will increment the rank.
at the end get the result set based on the rank.

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