Quiz for EXCEPT & MINUS

Q1: Which operator returns rows from the first query that are not present in the second?

A. UNION B. INTERSECT C. MINUS/EXCEPT D. JOIN

Q2: What does the EXCEPT operator do in SQL?

A. Returns all rows from first query that are also in the second B. Returns rows that are in both queries C. Returns rows from the first query that are not in the second D. Returns all rows from both queries

Q3: Which SQL database typically uses the MINUS operator instead of EXCEPT?

A. PostgreSQL B. Oracle C. MySQL D. SQLite

Q4: What must be true about the number of columns in both queries used with EXCEPT?

A. They can differ B. They must be the same C. Only the first query must have columns D. Only the second query must have columns

Q5: Which operator removes duplicate rows by default?

A. EXCEPT B. UNION ALL C. INTERSECT D. None of the above

Q6: Which operator can be used to simulate EXCEPT in MySQL?

A. LEFT JOIN with IS NULL B. INNER JOIN C. UNION D. CROSS JOIN

Q7: What is the result of a MINUS operation if all rows in the first query exist in the second?

A. All rows from the first query B. Duplicate rows C. Empty result set D. All rows from the second query

Q8: Can EXCEPT be used with ORDER BY clause?

A. Yes, after the last SELECT B. No C. Only with MINUS D. Only in subqueries

Q9: Which operator is not supported in MySQL natively?

A. UNION B. INTERSECT C. EXCEPT D. MINUS

Q10: What is a requirement for column data types in EXCEPT?

A. They must match exactly B. They must be convertible C. They must be numeric D. They must be strings

Q11: Which of the following is equivalent to EXCEPT in Oracle?

A. UNION B. INTERSECT C. MINUS D. LEFT JOIN

Q12: How many SELECT statements are required for using EXCEPT?

A. 1 B. 2 C. 3 D. Any number

Q13: What kind of operation is EXCEPT considered?

A. Join operation B. Set operation C. Aggregate operation D. Scalar operation

Q14: Which result is returned when combining EXCEPT with WHERE clause in both queries?

A. The full first query only B. Filtered rows not present in the second query C. All rows from both queries D. Rows present in both queries

Q15: Which databases support EXCEPT?

A. PostgreSQL B. SQL Server C. Oracle D. Both A and B

Q16: When is EXCEPT case-sensitive?

A. Always B. Never C. Depends on database collation D. Only with text data

Q17: What will be the result of SELECT 1 EXCEPT SELECT 1?

A. 1 B. 0 C. Empty result set D. Error

Q18: Which of the following returns unique rows only?

A. EXCEPT ALL B. EXCEPT C. UNION ALL D. None of these

Q19: What will happen if the column count differs in EXCEPT?

A. It throws an error B. It returns NULLs C. It ignores extra columns D. It auto-matches

Q20: Which clause cannot appear in individual SELECTs of EXCEPT?

A. ORDER BY B. GROUP BY C. HAVING D. LIMIT

Q21: Which keyword can simulate EXCEPT in MySQL using a workaround?

A. WHERE NOT EXISTS B. GROUP BY C. DISTINCT D. HAVING COUNT(*)