Database Modeling and Design MCQs with Answers
Practice important Database Modeling and Design MCQs with answers and explanations.
Multiple Choice Questions
Q241: What does the DELETE statement do?
- A: Deletes all rows from a table
- B: Deletes a specific row or rows from a table
- C: Updates data in a table
- D: Adds new rows to a table
View Answer
B
Q242: How can you delete all rows from a table?
- A: TRUNCATE TABLE TableName;
- B: UPDATE TableName SET column=value;
- C: INSERT INTO TableName VALUES ();
- D: DELETE FROM TableName;
View Answer
A
Q243: What is the difference between DELETE and TRUNCATE?
- A: DELETE can be faster than TRUNCATE
- B: TRUNCATE removes rows and retains the table structure
- C: DELETE removes rows and retains the table structure
- D: TRUNCATE removes rows and does not allow rollback
View Answer
B
Q244: What is a transaction in a database context?
- A: A unit of work performed against a database
- B: A method to update multiple columns
- C: A way to add new data
- D: A command to delete rows
View Answer
A
Q245: What does the COMMIT statement do?
- A: Undoes changes made to the database
- B: Saves all changes made during a transaction
- C: Deletes specific rows from the table
- D: Updates a single column in the table
View Answer
B
Q246: When is the ROLLBACK statement used?
- A: To save changes made in a transaction
- B: To undo changes made during a transaction
- C: To create a new table
- D: To modify existing data
View Answer
B
Q247: What does SQL stand for?
- A: Structured Query Language
- B: Sequential Query Language
- C: System Query Language
- D: Structured Query Logic
View Answer
A
Q248: Which SQL statement retrieves all columns from a table?
- A: SELECT * FROM table_name
- B: SELECT COLUMN FROM table_name
- C: SELECT ALL FROM table_name
- D: SELECT ALL COLUMNS FROM table_name
View Answer
A
Q249: What does the DISTINCT keyword do in SQL?
- A: Removes duplicate rows
- B: Sorts the results
- C: Filters rows based on a condition
- D: Changes the data type of a column
View Answer
A
Q250: Which SQL command is used to modify existing data in a table?
- A: UPDATE
- B: INSERT
- C: SELECT
- D: DELETE
View Answer
A