A walkthrough of a hard-level SQL interview problem involving splitting an employee hierarchy into teams using PostgreSQL. The solution uses a self-join to identify root-level direct reports as team anchors, then a recursive CTE to traverse the full hierarchy and assign each employee to their correct team. Key techniques include cross joins, left joins, COALESCE, ROW_NUMBER window functions, and STRING_AGG for final output formatting.
•21m watch time
1 Impression