Middle+
SELECT COUNT(DISTINCT employee_number) = COUNT(*) FROM employees
sobes.tech AI
Answer from AI
This SQL query:
SELECT COUNT(DISTINCT employee_number) = COUNT(*)
FROM employees
checks whether the number of unique values in the employee_number column is equal to the total number of rows in the employees table.
If the result is true (1), it means there are no duplicates in the employee_number column — each employee has a unique number.
If false (0), there are duplicate values.
This is a simple way to verify the uniqueness of data in a column without creating additional indexes or constraints.