Select the suitable option for retrieving all the employees who have a manager?
Answer options
A
SELECT empname, manager_id FROM employee WHERE manager_id IS NOT NULL;
B
SELECT * FROM employee WHERE manager_id = NULL;
C
SELECT * FROM employee WHERE manager_id != 0;
D
SELECT * FROM employee;
Correct answer: SELECT empname, manager_id FROM employee WHERE manager_id IS NOT NULL;
Detailed Solution & Conceptual Analysis
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Key Engineering Takeaway
In Database Management, understanding the underlying mechanics of Database Management is critical for writing performant, bug-free production code and passing rigorous technical architecture reviews.