Dataford
Interview QuestionsInterview GuidesExperiencesCoaching
New
Pricing
Get started
Dataford
Popular roles
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Browse
Browse All RolesEvery role hub, from analyst to MLBrowse All CompaniesCompany-specific interview loopsAll Interview GuidesThe full guide library
Top questions by role
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Top questions by skill
SQLPythonStatisticsMachine LearningA/B TestingSystem DesignGenerative AIProduct SenseMetricsBehavioral
Browse all questions →Try a mock interview
Experiences
Practice
Mock InterviewsTimed interview simulations with feedbackCoaching1:1 coaching with people at your target companiesSuccess PathYour 6-week structured planModulesCurated lessons by topicWebinarsTalks from ex-Big Tech data leadsPlaygroundA free-form scratch editor
Learn
BlogInterview strategy and career adviceTech Job Market ReportHiring trends across data and AI rolesFor UniversitiesDataford for career centersAbout DatafordWho we are and how we build
Pricing
Build my plan
Advanced Window Functions
00:00
5 left

Advanced Window Functions

MediumSQL · PostgreSQL

Problem

Write a SQL query using advanced window functions such as DENSE_RANK and RANK(). Asked in the Technical Round 2 stage. This was the first SQL question of round 2.

Use the provided employee, department, and assessment score data. Include active employees assigned to a department, treating missing completed scores as zero.

Output

  1. One row per included employee with department_name, employee_name, total_points, dense_rank, and rank.
  2. Rank employees within each department by total points descending. Tied employees share both ranks.
  3. Order by department_name, rank, then employee_id.

Schema

departments
ColumnTypeDescription
department_idPKINTUnique department identifier
department_nameVARCHAR(100)Department name
employees
ColumnTypeDescription
employee_idPKINTUnique employee identifier
employee_nameVARCHAR(100)Employee name
department_idINTAssigned department identifier
is_activeBOOLEANWhether the employee is active
assessment_scores
ColumnTypeDescription
score_idPKINTUnique assessment score identifier
employee_idINTEmployee receiving the score
pointsINTPoints earned for the assessment
completedBOOLEANWhether the assessment was completed
Tablesemployeesdepartmentsassessment_scores
Interviewer

Your question is Advanced Window Functions. 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
Sign up free to run your codeLog inLn 1
Run your query to see results here.