Inner vs Outer Join | Dataford Interview Questions

Inner join vs Outer join in databases.

Asked in the Round 1 stage. Using the provided departments and employees tables, write a query that lists every department and the number of employees assigned to it.

Output

One row per department with department_name and employee_count
Include departments with no assigned employees, showing a count of 0
Exclude employees whose department does not exist
Order by department_name alphabetically

Schema

departments

Column	Type	Description
department_idPK	INT	Unique department identifier
department_name	VARCHAR(100)	Department name

employees

Column	Type	Description
employee_idPK	INT	Unique employee identifier
employee_name	VARCHAR(100)	Employee name
department_id	INT	Assigned department identifier, when available
job_title	VARCHAR(100)	Employee job title

Your question is Inner vs Outer Join. Start with the requirements and the two tables in the Question tab.

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