The number of rows returned by SQL query on the given EMP table is ________…
2025
The number of rows returned by SQL query on the given EMP table is ________
SELECT *
FROM EMP
WHERE eno NOT IN (
SELECT manager FROM EMP);
- A.
0
- B.
1
- C.
3
- D.
error
Attempted by 124 students.
Show answer & explanation
Correct answer: B
Step 1: The subquery SELECT manager FROM EMP returns the values 2, 3, 4, and NULL. Step 2: The main query SELECT * FROM EMP WHERE eno NOT IN (2, 3, 4, NULL) checks for eno values not in this list. Step 3: The eno values in the EMP table are 1, 2, 3, and 4. Step 4: eno = 1 is not in the list (2, 3, 4, NULL), so it is included. Step 5: eno = 2 is in the list, so it is excluded. Step 6: eno = 3 is in the list, so it is excluded. Step 7: eno = 4 is in the list, so it is excluded. Step 8: Only the row with eno = 1 is returned, so the count is 1.