Done SQL 5

[sakshiasati17]

No description provided.

[super30admin]

1. Correctness:

   • Average_Salary_Department_vs_Company.sql: The solution correctly calculates department and company averages and compares them. It handles the comparison logic well.
   • Game_Play_Analysis_I.sql: Correctly identifies the first login date for each player.
   • Report_Contiguos_Dates.sql: The approach to identify contiguous date ranges is correct but could be simplified.
   • Student_Report_By_Geography.sql: Correctly pivots the data by continent but could handle NULL values more elegantly.

2. Time Complexity:

   • All solutions use appropriate joins and aggregations, resulting in reasonable time complexity (generally O(n) or O(n log n) for the operations used).

3. Space Complexity:

   • The solutions create temporary tables/CTEs which use additional space, but this is necessary for the operations being performed.

4. Code Quality:

   • The code is generally well-structured and readable.
   • Consistent indentation and formatting.
   • Good use of CTEs for complex queries.
   • Could improve with more descriptive aliases (e.g., 'ds' and 'cs' in the first query could be more meaningful).

5. Efficiency:

   • Report_Contiguos_Dates.sql could be simplified by using LAG/LEAD functions instead of the current approach with multiple CTEs.
   • Student_Report_By_Geography.sql could use COALESCE or IFNULL to handle NULL values more cleanly.
   • All queries would benefit from proper indexing on join and filter columns.