Quizz on DBMS Class-XIIBy admin / December 2, 2025 Quizz on DBMS Class-XII Important MCQs Quizz on DBMS 1 / 30 Which of the following is an example of a DBMS? A) MS Word B) Python C) PowerPoint D) MySQL 2 / 30 commit() is required for ______ operations. A) Insert B) Update C) Delete D) All of these 3 / 30 IN operator is used to ______. A) Match any value from a list B) Check range C) Count items D) Join tables 4 / 30 SELECT COUNT(*) returns ______. A) Number of columns B) Number of tables C) Number of rows D) Maximum value 5 / 30 HAVING clause is used with ______. A) Conditions on rows B) Conditions on groups C) Both D) None 6 / 30 WHERE clause is applied ______ GROUP BY. A) Before B) After C) With D) None of these 7 / 30 Natural join removes ______. A) Duplicate rows B) NULL values C) Duplicate column names D) All of these 8 / 30 A join that produces all combinations of two tables is ______. A) Equi join B) Natural join C) Cartesian product D) Outer join 9 / 30 To add a new column ‘age’, use: A) ALTER TABLE t ADD age INT; B) UPDATE TABLE t ADD age INT; C) INSERT COLUMN age; D) ADD COLUMN age; 10 / 30 To modify the structure of a table, use ______. A) CHANGE B) UPDATE C) MODIFY TABLE D) ALTER TABLE 11 / 30 The wildcard character for any number of characters in LIKE is ______. A) _ B) % C) # D) * 12 / 30 SELECT DISTINCT is used to remove ______. A) MAX values B) NULL rows C) Duplicate rows D) Constraints 13 / 30 SUM() is a/an ______ function. A) Mathematical B) Logical C) Aggregate D) String 14 / 30 To sort data in ascending or descending, we use ______ clause. A) SORT BY B) ORDER BY C) GROUP BY D) HAVING 15 / 30 NULL means ______. A) Zero B) Empty string C) No value D) Space 16 / 30 To remove an entire table, we use ______. A) REMOVE TABLE B) DELETE TABLE C) ERASE TABLE D) DROP TABLE 17 / 30 NOT NULL is a ______. A) Operator B) Function C) Constraint D) Command 18 / 30 Which of the following is a DML command? A) CREATE B) DELETE C) DROP D) ALTER 19 / 30 A table can have ______ primary key(s). A) 0 B) 1 C) 2 D) Many 20 / 30 Alternate key is ______. A) Foreign key B) Another primary key C) A candidate key not chosen as primary key D) Duplicate key 21 / 30 A foreign key refers to ______. A) Primary key in same table B) Primary key in another table C) Unique key D) Candidate key 22 / 30 A candidate key is ______. A) Key with highest value B) Minimal set of attributes that uniquely identify tuples C) Redundant key D) None 23 / 30 A primary key must be ______. A) Unique B) Not Null C) Optional D) Both A & B 24 / 30 Domain refers to ______. A) Set of allowed values B) Column name C) Row value D) Table size 25 / 30 The number of rows in a relation is called ______. A) Cardinality B) Degree C) Domain D) Tuple Count 26 / 30 The number of columns in a relation is called ______. A) Cardinality B) Degree C) Domain D) Attribute 27 / 30 Columns in a table are called ______. A) Attributes B) Tuples C) Fields D) Both A & C 28 / 30 Rows in a table are called ______. A) Attributes B) Tuples C) Domains D) Keys 29 / 30 Data redundancy means ______. A) Data stored multiple times B) No data stored C) Unique data D) Data not consistent Redundancy = unnecessary repetition of data. 30 / 30 A table in a database is called a ______. A) Entity B) Attribute C) Relation D) Tuple Your score isThe average score is 68% 0% Restart quiz