Completed Sql5

[DhruvParashar246]

No description provided.

[super30admin]

1. Correctness:

   • The "Average Salary Department vs Company" solution correctly calculates and compares department vs company averages using CTEs and JOINs.
   • "Game Play Analysis I" correctly finds the first login date for each player.
   • "Report Contiguous Dates" correctly identifies contiguous periods of success/failure using window functions.
   • "Student Report by Geography" correctly pivots student data by continent using ROW_NUMBER() and joins.

2. Time Complexity:

   • All solutions use appropriate operations (GROUP BY, JOIN, window functions) with expected O(n log n) or O(n) complexity for typical database operations.

3. Space Complexity:

   • The solutions create temporary tables (CTEs) but release them after execution, so space complexity is reasonable.

4. Code Quality:

   • Generally well-structured with clear CTE naming.
   • Some improvements could be made:
     • In "Average Salary Department vs Company", the GROUP BY should include the month from the pay_date.
     • In "Student Report by Geography", the RIGHT JOIN could be simplified to LEFT JOIN since 'first' is the primary table.
     • Consistent formatting (some queries use AS for aliases, others don't).
     • The CASE statement in the first solution could be formatted more clearly.

5. Efficiency:

   • All solutions are efficient for their respective problems.
   • The "Report Contiguous Dates" solution could potentially be optimized by combining some CTEs.