This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Modification of Database”. 1. A Delete command operates on ______ relation. a) One b) Two c) Several d) Null 2. Delete from r where P; The above command a) Deletes a particular tuple from the relation b) Deletes the relation c) Clears all … Read more
This set of Database Questions and Answers focuses on “Aggregate Functions and Nested Subqueries – 2”. 1. SELECT dept_name, ID, avg (salary) FROM instructor GROUP BY dept_name; This statement IS erroneous because a) Avg(salary) should not be selected b) Dept_id should not be used in group by clause c) Misplaced group by clause d) Group … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Aggregate Functions and Nested Subqueries – 1”. 1. Aggregate functions are functions that take a ___________ as input and return a single value. a) Collection of values b) Single value c) Aggregate value d) Both Collection of values & Single value 2. SELECT … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Null Values Operations”. 1. A _____ indicates an absent value that may exist but be unknown or that may not exist at all. a) Empty tuple b) New value c) Null value d) Old value 2. If the attribute phone number is included … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Set Operations”. 1. The union operation is represented by a) ∩ b) U c) – d) * 2. The intersection operator is used to get the _____ tuples. a) Different b) Common c) All d) Repeating 3. The union operation automatically __________ unlike … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Basic SQL Operations”. 1. SELECT name ____ instructor name, course id FROM instructor, teaches WHERE instructor.ID= teaches.ID; Which keyword must be used here to rename the field name? a) From b) Rename c) As d) Join 2. SELECT * FROM employee WHERE dept_name="Comp … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “SQL Queries”. 1. Name Annie Bob Callie Derek Which of these query will display the the table given above ? a) Select employee from name b) Select name c) Select name from employee d) Select employee 2. Here which of the following displays … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “SQL Basics and SQL Data Definition”. 1. Which one of the following is used to define the structure of the relation, deleting relations and relating schemas? a) DML(Data Manipulation Langauge) b) DDL(Data Definition Langauge) c) Query d) Relational Schema 2. Which one of … Read more
This set of Database MCQs focuses on “Relational Query Operations and Relational Operators”. 1. Using which language can a user request information from a database? a) Query b) Relational c) Structural d) Compiler 2. Student(ID, name, dept name, tot_cred) In this query which attributes form the primary key? a) Name b) Dept c) Tot_cred d) … Read more
This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “Keys”. 1. Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record? a) Candidate key b) Sub key c) Super key d) Foreign key 2. Consider attributes ID, CITY and NAME. Which one … Read more
