DBMS_QUESTION_BANK.pdf

DBMS MCQ QUESTION BANK 1. What is the func on of the external level in database architecture? A) Describes the physical storage of data B) Defines how users view the data C) Provides internal schema D) Manages hardware resources Answer: B 2. Which of the following operators ret...

DBMS MCQ QUESTION BANK 1. What is the func on of the external level in database architecture? A) Describes the physical storage of data B) Defines how users view the data C) Provides internal schema D) Manages hardware resources Answer: B 2. Which of the following operators returns TRUE if any of the condi ons are true? A) AND B) OR C) NOT D) BETWEEN Answer: B 3. What is the role of the DBA (Database Administrator)? A) Wri ng applica on programs B) Managing and maintaining database resources C) Designing the network architecture D) Conduc ng backups Answer: B 4. What does DBMS stand for? A) Database Memory System B) Database Management System C) Data Backup System D) Data Manipula on System Answer: B 5. Which SQL command is used to add new rows to a table? A) INSERT INTO B) UPDATE C) SELECT D) DELETE Answer: A 6. What is the main purpose of DBMS? A) To store large amounts of data in tables B) To provide data security C) To manage data and ensure data integrity D) To provide memory storage Answer: C 7. Which SQL command is used to modify exis ng data in a table? A) INSERT INTO B) ALTER C) UPDATE D) DELETE Answer: C 8. Which SQL keyword is used to find values within a specific range? A) BETWEEN B) IS NULL C) LIKE D) IN Answer: A 9. Which of the following is a special operator used to test for null values in SQL? A) IS NULL B) LIKE C) IN D) BETWEEN Answer: A 10. What is the primary characteris c of a 3- er database architecture? A) Database and client are on the same machine B) Applica on layer separates user interface and database C) Direct interac on between client and database D) Database is shared by mul ple applica ons Answer: B 11. Which of the following is not a type of data model? A) Rela onal data model B) E-R data model C) Hierarchical data model D) Linear data model Answer: D 12. What is the purpose of the WHERE clause in a SELECT query? A) To specify columns to retrieve B) To specify condi ons for filtering rows C) To sort the result set D) To group data Answer: B 13. Which of the following is an example of data independence? A) Separa on of data from applica on B) Lack of data redundancy C) Data shared between mul ple users D) Data stored on mul ple servers Answer: A 14. Which of the following is not an applica on of DBMS? A) Banking systems B) Video streaming C) Social media D) Compiler design Answer: D 15. How do you permanently save data in a database a er adding or upda ng rows? A) COMMIT B) ROLLBACK C) SAVE D) EXIT Answer: A 16. In the hierarchical data model, the data is organized in a: A) Tree-like structure B) Graph-like structure C) Table format D) Array format Answer: A 17. Which SQL command is used to retrieve data from a database? A) UPDATE B) SELECT C) INSERT D) DELETE Answer: B 18. What is the func on of the internal level in database architecture? A) Describes how users view the data B) Defines the logical structure of the database C) Manages the physical storage of data D) Provides interac on with the applica on Answer: C 19. What is the purpose of aggregate func ons in SQL? A) To calculate totals and summaries for data B) To retrieve specific rows C) To group data for complex queries D) To create subqueries Answer: A 20. What is the role of the conceptual level in database architecture? A) Defines user views B) Describes how data is stored C) Provides internal schema D) Describes the en re database structure Answer: D 21. Which SQL operator is used to filter data based on pa ern matching? A) BETWEEN B) LIKE C) IN D) IS NULL Answer: B 22. What is the purpose of the SELECT query in SQL? A) To insert new data B) To retrieve data C) To update exis ng data D) To delete data Answer: B 23. Which command is used to remove rows from a table? A) UPDATE B) DELETE C) INSERT D) DROP Answer: B 24. Which of the following is not a SQL aggregate func on? A) SUM B) COUNT C) MAX D) MODIFY Answer: D 25. In the 2- er architecture, what is the role of the applica on layer? A) Manages direct database interac ons B) Acts as an intermediary between user interface and database C) Handles user authen ca on D) Stores the database Answer: B 26. What command is used to modify the structure of an exis ng table in SQL? A) UPDATE B) MODIFY C) ALTER D) INSERT Answer: C 27. Which of the following operators is used to combine mul ple condi ons in a SELECT query? A) AND B) != C) IN D) || Answer: A 28. What is the main purpose of database mappings? A) To link external schema with internal schema B) To define database objects C) To describe physical storage D) To provide user authen ca on Answer: A 29. What is the role of a foreign key in a rela onal database? A) To link two tables B) To uniquely iden fy rows C) To create views D) To aggregate data Answer: A 30. Which SQL clause is used to filter rows returned by a query? A) WHERE B) HAVING C) ORDER BY D) LIMIT Answer: A 31. What is the purpose of the IS NULL operator in SQL? A) To find NULL values in a column B) To find non-NULL values in a column C) To update rows D) To add rows Answer: A 32. Which of the following is true about hierarchical data models? A) Data is arranged in a table format B) It organizes data in a tree-like structure C) It uses rela onal algebra for opera ons D) Data is stored as network nodes Answer: B 33. What command is used to remove a table from a database? A) DELETE B) DROP C) REMOVE D) ALTER Answer: B 34. Which of the following commands is used to modify the structure of an exis ng table? A) ALTER B) UPDATE C) INSERT D) SELECT Answer: A 35. In database systems, what is meant by "data independence"? A) Changing the storage schema without affec ng the external schema B) Changing data in the database without affec ng the DBMS C) Altering hardware resources for be er performance D) Ensuring data security from unauthorized access Answer: A 36. What SQL keyword is used to select records that match a specific pa ern? A) IN B) BETWEEN C) LIKE D) IS NULL Answer: C 37. Which SQL command is used to remove specific rows from a table? A) DROP B) DELETE C) ALTER D) TRUNCATE Answer: B 38. What is the func on of the internal level in a database system? A) To describe the database structure at the logical level B) To define how data is physically stored C) To specify user views of the data D) To provide mappings between internal and external schemas Answer: B 39. Which of the following operators is used to check if a value exists within a list of values? A) BETWEEN B) IN C) LIKE D) IS NULL Answer: B 40. In which architecture level does the user directly interact with the DBMS? A) Internal Level B) External Level C) Conceptual Level D) Storage Level Answer: B 41. Which of the following is a DML command in SQL? A) CREATE B) UPDATE C) ALTER D) DROP Answer: B 42. What is the purpose of the GROUP BY clause in SQL? A) To group rows that have the same values into summary rows B) To filter rows before aggrega on C) To update rows in a table D) To sort rows in a query Answer: A 43. What is the purpose of the DISTINCT keyword in SQL? A) To filter rows that are iden cal B) To retrieve only unique values C) To sort data in a unique way D) To group rows Answer: B 44. What does DDL stand for in the context of SQL? A) Data Defini on Language B) Data Descrip on Language C) Data Deriva on Language D) Data Delete Language Answer: A 45. Which of the following is a logical operator used in SQL? A) ADD B) OR C) BETWEEN D) INSERT Answer: B 46. What is the func on of PRIMARY KEY in SQL? A) To ensure the uniqueness of each record in a table B) To relate tables in a database C) To add a new column to a table D) To delete a table Answer: A 47. Which SQL func on is used to count the number of rows in a table? A) COUNT() B) SUM() C) MAX() D) AVG() Answer: A 48. What is the key characteris c of a rela onal data model? A) Data is stored as records and rela onships between them are shown using a graph B) Data is stored in tables with rows and columns C) Data is stored hierarchically D) Data is stored in a network structure Answer: B 49. Which SQL command is used to rename a column in a table? A) RENAME B) UPDATE C) ALTER D) MODIFY Answer: C 50. What is the func on of a foreign key in a rela onal database? A) To uniquely iden fy a row in a table B) To ensure data integrity between two tables C) To add a new record to the database D) To perform aggrega on Answer: B 51. Which of the following allows grouping of rows based on specific column values? A) HAVING B) WHERE C) GROUP BY D) ORDER BY Answer: C 52. In SQL, what does DROP do to a table? A) Removes data from the table B) Deletes the table structure along with data C) Modifies the table structure D) Changes the table name Answer: B 53. Which of the following commands is used to update data in an SQL table? A) INSERT INTO B) DELETE C) UPDATE D) ALTER Answer: C 54. Which of the following constraints ensures that all records in a column are unique? A) PRIMARY KEY B) UNIQUE C) FOREIGN KEY D) NOT NULL Answer: B 55. Which SQL operator is used to match a value to any value in a list? A) LIKE B) IN C) BETWEEN D) IS NULL Answer: B 56. What is the func on of NOT NULL constraint in SQL? A) Ensures that the column does not accept NULL values B) Ensures the uniqueness of records C) Enforces referen al integrity D) Ensures the foreign key rela onship Answer: A 57. What is the func on of the COMMIT statement in SQL? A) To apply and save changes made to the database B) To roll back changes C) To delete a table D) To drop a database Answer: A 58. What is a VIEW in SQL? A) A virtual table based on the result-set of a query B) A physical table C) A way to add new data D) A way to delete data Answer: A 59. What is the purpose of the HAVING clause in SQL? A) To filter groups based on aggregate func ons B) To update data in a table C) To specify condi ons for sor ng D) To retrieve dis nct rows Answer: A 60. Which of the following represents the logical design of a database? A) E-R Diagram B) Network Diagram C) Flowchart D) Block Diagram Answer: A