DataBase Management System

Structured Query Language

⛪ Computer Science and Engineering > DataBase Management System

SQL stands for structured query language. It is a language that can be used for retrieval and management of data stored in relational database. It is a non-procedural language as it specifies what is to be retrieved rather than how to retrieve it. It can be used for defining the structure of data, modifying data in the database and specifying the security constraints.

The two major categories of SQL commands are Data Definition Language (DDL) and Data Manipulation Language (DML). DDL provides commands that can be used to create, modify and delete database objects. DML provides commands that can be used to access and manipulate the data, that is, to retrieve, insert, delete and update data in a database.

Improve your understanding of Structured Query Language (SQL) with our interactive and challenging MCQ (Multiple Choice Questions) quiz. Covering a range of topics, from basic queries to advanced SQL features, our quiz is designed to help you practice your skills and prepare for interviews or exams.

➲ Structured Query Language - Quiz

Q 1: Which of the following constraints ensures that the foreign key value in the referencing relation must exist in the primary key attribute of the referenced relation?

  • A Unique Key
  • B Reference Key
  • C Foreign key
  • D Primary key

Q 2: Which of the following SQL statements will return all the tuples from a relation named Employee sorted in the descending order of Name?

  • A SELECT * FROM Employee SORT BY
  • B SELECT * FROM Employee ORDER BY Name DESC;
  • C SELECT * FROM Employee ORDER Name DESC;
  • D SELECT * FROM Employee SORT

Q 3: Which of these keywords is used to eliminate duplicate tuples from the resultant relation?

  • A DELETE
  • B DISTINCT
  • C NON DUPLICATE
  • D EXISTS

Q 4: Which of these operators selects values that match any value in a given list of values?

  • A BETWEEN
  • B LIKE
  • C IN
  • D None of these

Q 5: Which of these characters is used to match a substring with any number of characters?

  • A %
  • B ?
  • C _
  • D *

Q 6: The operation that is used to retrieve those tuples present in one relation, and not present in another relation is___________.

  • A UNION
  • B INTERSECT
  • C MINUS
  • D DIFFERENCE

Q 7: Which of these is the correct command for inserting values in the Employee relation?

  • A INSERT VALUES (
  • B INSERT (
  • C INSERT INTO Employee VALUES (
  • D None of these

Q 8: The command that can be used to make changes in the name of publishers in a relation PUBLISHER is____________.

  • A UPDATE
  • B None of these
  • C ALTER
  • D MODIFY

Q 9: Which of these is the correct command to change "Jon" into "John" in the Name attribute of the Employee relation?

  • A UPDATE Employee SET Name=
  • B ALTER Employee SET Name=
  • C UPDATE Employee SET Name=
  • D ALTER Employee SET Name=

Q 10: Consider the following SQL statements: (I) DELETE FROM Customer; (II) DROP TABLE Customer;

  • A Only statement (I) permanently removes the relation Customer
  • B Only statement (II) permanently removes the relation Customer
  • C Both statements (I) and (II) permanently remove the relation Customer
  • D None of these

Q 11: Which of the following is the valid SQL statement? (a) SELECT * FROM Employee WHERE email_id IS NULL;

  • A All of these
  • B SELECT * FROM Employee WHERE email_id IS NULL;
  • C SELECT * FROM Employee WHERE IS NULL (email_id);
  • D SELECT * FROM Employee WHERE email_id NULL;

Q 12: Which of the following will return the number of tuples in the Employee relation?

  • A SELECT COLUMNS(*) FROM Employee;
  • B SELECT COUNT()FROM Employee;
  • C SELECT COUNT(*)FROM Employee;
  • D All of these

Q 13: Which of these statements is true? (i) The contents of view are derived from already existing relations (ii) View like any other relation forms the part of database schema (iii) A view can be queried, inserted into, deleted from and joined with other relations or views

  • A Only (i) is true
  • B Only (i) and (iii) are true
  • C Only (ii) and (iii) are true
  • D (i), (ii) and (iii) are true

Q 14: Which of these mechanisms provides a way to retrieve multiple tuples from a relation and then process each tuple individually in a host program?

  • A Triggers
  • B Cursors
  • C Assertions
  • D None of these

Q 15: Which of the following clauses is used to restrict groups returned by the GROUP BY clause?

  • A DISTINCT
  • B WHERE
  • C EXISTS
  • D HAVING