Dataford
Interview QuestionsInterview GuidesExperiencesMock InterviewsPricing
Get started
Top N Query with Complex Criteria
00:00
5 left

Top N Query with Complex Criteria

MediumSQL · PostgreSQL

Problem

Given a specific table structure, write a query to fetch the top N records based on a complex criteria.

Use the provided tables and evaluate records through 2025-03-31. Return entities with at least two active terminals and at least 1,000 in qualifying net volume. Rank them by net volume descending, then March-over-February growth descending, then entity ID ascending.

Output

  1. One row per selected entity with columns entity_id, entity_name, net_volume, active_terminal_count, and growth_pct
  2. Include only the top three qualifying entities
  3. Sort by the stated ranking rules

Schema

entities
ColumnTypeDescription
entity_idPKINTUnique entity identifier
entity_nameVARCHAR(100)Entity display name
terminals
ColumnTypeDescription
terminal_idPKINTUnique terminal identifier
entity_idINTOwning entity
activated_atDATEDate the terminal became active
deactivated_atDATEDate the terminal became inactive
transactions
ColumnTypeDescription
transaction_idPKINTUnique transaction identifier
entity_idINTEntity associated with the transaction
terminal_idINTTerminal that processed the transaction
occurred_atDATETransaction date
amountNUMERIC(12,2)Signed transaction amount
statusVARCHAR(20)Transaction status
Tablesentitiesterminalstransactions
Interviewer

Your question is Top N Query with Complex Criteria. Start with the requirements and the three tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

You need to log in / sign up to run or submit.
CodePostgreSQL
You need to log in / sign up to run or submit.Ln 1
Run your query to see results here.