Database

• Collect requirements
• Research tools and libraries
• Write code
• Test, diagnose problems, and correct errors.
• Repeat above until working

WITH CTE_fingerprint
AS (
	SELECT 
		employee_number
		,created_date
		,created_time
		,ROW_NUMBER() OVER (
		PARTITION BY
			employee_number
			,created_date
			,created_time
		ORDER BY 
			 employee_number
			,created_date
			,created_time
			) AS RowNumber
	FROM [fingerprint]
	)

DELETE
FROM CTE_fingerprint
WHERE RowNumber > 1;

SELECT *
FROM fingerprint t1 inner join fingerprint t2 on
t1.created_date=t2.created_date and t1.created_time = t2.created_time and t1.employee_number=t2.employee_number
Where t1.ID<t2.ID

DELETE 
FROM fingerprint
WHERE fingerprint.ID IN
(
    SELECT t1.ID
    FROM ... (see query above)
)

SELECT LEFT(PhoneNumber, 2) + '******' + RIGHT(PhoneNumber, 2)
  FROM AdventureWorks.Person.PersonPhone

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

SELECT employee_leaves.leave_from, employee_leaves.leave_to FROM employee_leaves
JOIN leave_category ON leave_category.leave_category_id = employee_leaves.leave_category
GROUP BY YEAR(employee_leaves.leave_from);