Count Specific Names in SQL | Dataford Interview Questions

Transaction Network Services wants a quick validation query for employee records assigned to active operational units. Write a PostgreSQL query that counts employees whose exact first_name value is Jack and whose department is active.

Requirements

Join employees to departments using department_id.
Match the exact first name Jack, preserving PostgreSQL's case-sensitive comparison.
Include only employees assigned to departments where is_active is TRUE.
Return one row with the count aliased as jack_count.

Schema

employees

Column	Type	Description
employee_idPK	INT	Unique employee identifier
first_name	VARCHAR(100)	Employee's first name
department_id	INT	Assigned department identifier

departments

Column	Type	Description
department_idPK	INT	Unique department identifier
department_name	VARCHAR(150)	TNS department name
is_active	BOOLEAN	Whether the department is currently active

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