Advanced SQL problems
- 1. A CASE SQL statement is which of the following?
Options- A. A way to establish an IF-THEN-ELSE in SQL.
- B. A way to establish a loop in SQL.
- C. A way to establish a data definition in SQL.
- D. All of the above. Discuss
Correct Answer: A way to establish an IF-THEN-ELSE in SQL.
- 2. Which of the following statements is true concerning routines and triggers?
Options- A. Both consist of procedural code.
- B. Both have to be called to operate.
- C. Both run automatically.
- D. Both are stored in the database. Discuss
Correct Answer: Both consist of procedural code.
- 3. The following SQL is which type of join: SELECT CUSTOMER_T. CUSTOMER_ID, ORDER_T. CUSTOMER_ID, NAME, ORDER_ID FROM CUSTOMER_T,ORDER_T ;
Options- A. Equi-join
- B. Natural join
- C. Outer join
- D. Cartesian join Discuss
Correct Answer: Cartesian join
- 4. How many tables may be included with a join?
Options- A. One
- B. Two
- C. Three
- D. All of the above. Discuss
Correct Answer: All of the above.
- 5. Which of the following is a correlated subquery?
Options- A. Uses the result of an inner query to determine the processing of an outer query.
- B. Uses the result of an outer query to determine the processing of an inner query.
- C. Uses the result of an inner query to determine the processing of an inner query.
- D. Uses the result of an outer query to determine the processing of an outer query. Discuss
Correct Answer: Uses the result of an outer query to determine the processing of an inner query.
Explanation:
Correlated subquery references a column in the outer query and executes the subquery once for every row in the outer query while Uncorrelated subquery executes the subquery first and passes the value to the outer query.
- 6. The joining technique is useful when data from several relations are to be retrieved and displayed and the relationships are not necessarily nested.
Options- A. True
- B. False Discuss
Correct Answer: True
- 7. There should be one condition within the WHERE clause for each pair of tables being joined.
Options- A. True
- B. False Discuss
Correct Answer: True
- 8. A transaction is the complete set of closely related update commands that must all be done, or none of them done, for the database to remain valid.
Options- A. True
- B. False Discuss
Correct Answer: True
- 9. A correlated subquery is where the outer query depends on data from the inner query.
Options- A. True
- B. False Discuss
Correct Answer: False
- 10. The code to create triggers and routines is stored in only one location and is administered centrally.
Options- A. True
- B. False Discuss
Correct Answer: True
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