Employee Dataset SQL Queries | Dataford Interview Questions

Write SQL queries on an employee dataset containing columns like eid, name, manager_yes_no, report_to_whom, date_hired.

Asked in the Technical Phone Screen stage. The hiring manager pasted SQL questions one by one into an internal Amazon online text document while the candidate coded responses live.

Task

Write PostgreSQL queries against the employee table to identify reporting relationships and hire-date patterns.

Requirements

Return employees who are managers and the number of direct reports they have.
Return employees who do not report to anyone, based on report_to_whom being NULL.
Return employees hired in the earliest month present in the data, ordered by hire date.

Output

Return one result set for each requirement, with the appropriate columns and ordering.

Schema

employee

Column	Type	Description
eidPK	INT	Unique employee identifier
name	VARCHAR(100)	Employee full name
manager_yes_no	VARCHAR(3)	Whether the employee is a manager, values like Yes or No
report_to_whom	INT	Employee ID of the direct manager, nullable for top-level employees
date_hired	DATE	Hire date

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