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Top Courses by Category
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Top Courses by Category

HardSQL · PostgreSQL

Problem

Write a query to find the top three most popular courses in each technology category based on monthly active learners at Pluralsight.

Use the provided course and learner activity data. Include only courses with at least one identified learner activity in a month.

Output

  1. One row per included month, technology category, and course.
  2. Columns: activity_month, technology_category, course_id, course_title, monthly_active_learners, and popularity_rank.
  3. Return the top three courses per month and category, ordered by activity_month, technology_category, and popularity_rank.

Schema

courses
ColumnTypeDescription
course_idPKINTUnique course identifier
course_titleVARCHAR(150)Course title shown in Pluralsight
technology_categoryVARCHAR(80)Technology category assigned to the course
course_learner_activity
ColumnTypeDescription
activity_idPKINTUnique learner activity record
course_idINTCourse associated with the activity
learner_idINTLearner associated with the activity
activity_monthDATEMonth of activity, stored as the first day of the month
Tablescoursescourse_learner_activity
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Your question is Top Courses by Category. Start with the requirements and the two tables in the Question tab.

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