Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Multiple Choice Questions
Q421: Which SQL data type is most appropriate for storing decimal values with fixed precision?
- A: DECIMAL
- B: CHAR
- C: INT
- D: FLOAT
View Answer
A
Q422: What is the purpose of the REFERENCES keyword in SQL table creation?
- A: To define the primary key
- B: To create an index
- C: To define a foreign key
- D: To delete a table
View Answer
C
Q423: Fill in the blank: The ON DELETE CASCADE clause is used to ______.
- A: Update a table
- B: Automatically delete related records
- C: Prevent delete operations
- D: Insert new rows
View Answer
B
Q424: What does the ALTER TABLE statement do in SQL?
- A: Adds constraints
- B: Modifies an existing table
- C: Deletes tables
- D: Inserts new rows
View Answer
B
Q425: Which command is used to delete all rows from a table in SQL?
- A: DELETE
- B: DROP
- C: TRUNCATE
- D: ALTER
View Answer
C
Q426: The ALTER TABLE statement cannot ______.
- A: Add columns
- B: Modify column types
- C: Delete a column
- D: Add multiple columns at once
View Answer
D
Q427: In the ALTER TABLE statement, which option is used to rename a column?
- A: ALTER COLUMN
- B: RENAME COLUMN
- C: DROP COLUMN
- D: SET DEFAULT
View Answer
B
Q428: What happens when the TRUNCATE command is executed on a table?
- A: Deletes table
- B: Deletes all rows but keeps the structure
- C: Deletes specific rows
- D: Deletes rows conditionally
View Answer
B
Q429: Which of the following SQL commands is used to add records to a table?
- A: SELECT
- B: INSERT
- C: DELETE
- D: UPDATE
View Answer
B
Q430: The DELETE command in SQL does what?
- A: Adds new rows
- B: Deletes records conditionally
- C: Deletes the entire table
- D: Modifies existing rows
View Answer
B