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Window Function for Top Drivers
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Window Function for Top Drivers

MediumSQL · PostgreSQL

Problem

Identify the top 10% of drivers by earnings using a window function.

Calculate each driver's total earnings from completed rides, including drivers with no completed rides. Treat missing earnings as zero and use all available ride records.

Output

  1. One row per driver in the top earnings decile
  2. Columns: driver_id, driver_name, and total_earnings
  3. Sort by total_earnings descending, then driver_id ascending for deterministic tie-breaking

Schema

drivers
ColumnTypeDescription
driver_idPKINTUnique driver identifier
driver_nameVARCHAR(100)Driver's name
rides
ColumnTypeDescription
ride_idPKINTUnique ride identifier
driver_idINTDriver assigned to the ride
earningsNUMERIC(10,2)Driver earnings for the ride
statusVARCHAR(20)Ride status
Tablesdriversrides
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