577 Employee Bonus

To find employees with a bonus less than 1000, we need to consider cases where an employee has no bonus at all.

Approach

1. Perform a LEFT JOIN:
   • We join Employee and Bonus tables using empID:

   FROM Employee AS e
   LEFT JOIN Bonus AS b
   ON e.empID = b.empID
   

   • Since Employee contains all employees, the LEFT JOIN ensures that employees without a corresponding Bonus record will have NULL values in the Bonus column.
2. Apply filtering condition:
   • We need to select employees where the bonus is either below 1000 or does not exist (NULL):

   WHERE b.bonus < 1000 OR b.bonus IS NULL
   

Conclusion

This ensures that we correctly filter out all employees whose bonus is either below 1000 or who have no bonus at all.