Free Databases MCQs with Answers

• A. Primary Key
• B. Foreign Key
• C. Super Key
• D. Composite Key

Explanation: A candidate key is a minimal set of attributes that can uniquely identify a tuple (or row) in a relation (or table) in a database.In…

• A. It must be unique
• B. It helps in indexing of large database
• C. It makes sorting quicker
• D. All of these

Explanation: A primary key is a column (or set of columns) in a database table that uniquely identifies each row in the table.

• A. A person's last name
• B. An employee salary
• C. A customer's Id
• D. A sale's person region

Explanation: The correct answer is (c) A customer's ID number.A primary key is a field (or set of fields) in a database table that uniquely identifies…

• A. Data Manager
• B. SQL
• C. Report Generators
• D. Utilities

Explanation: SQL (b) is used to create data views. SQL (Structured Query Language) is a programming language designed for managing data in relational…

• A. Secondary key
• B. Foreign Key
• C. Candidate Key
• D. Primary Key

Explanation: A foreign key is a column or group of columns in a relational database table that references the primary key of another table.

• A. Join
• B. Data Integration
• C. Relationship
• D. Keys

Explanation: A Key can be a single attribute or a group of attributes, where the combination may act as a key.

• A. Each row is unique
• B. The order column is significant
• C. The order of rows is insignificant
• D. Columns are all elemental or atomic

Explanation: A table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being…

• A. Improve the performance of data base
• B. Document the structure of database itself
• C. Reduce data dependancy for application program
• D. All of these

Explanation: Indexes in a database management system (DBMS) are data structures that improve the speed of data retrieval operations on a table.

• A. Each attribute has a unique name
• B. No two rows in a relation are Identical
• C. There are no multivalued attributes in a relation
• D. All of the above

Explanation: Improve the performance of the database: This is the most common reason to create indexes.

• A. A key that identifies only one record
• B. The most important field in a record
• C. The first field of tha table
• D. Redundant field

Explanation: A Key can be a single attribute or a group of attributes, where the combination may act as a key.

• A. Indivisible
• B. Different
• C. Divisible
• D. Constant

Explanation: In the context of databases, a domain is considered atomic if its elements are considered indivisible units.

• A. Global key
• B. Link key
• C. Foreign key
• D. Super key

Explanation: A foreign key is a field in one table that uniquely identifies a row of another table or the same table.

• A. Data definition
• B. Data Manipulation
• C. Data definition and Manipulation
• D. Searching records

Explanation: SQL is a domain-specific language used in programming and designed for managing data held in a relational database management system, or…

• A. Parabola
• B. Parallelogram
• C. Ellipse
• D. Rectangular

Explanation: In an Entity-Relationship (ER) diagram, attributes are represented by ellipses or ovals connected to their respective entity.

• A. Secondary Key
• B. Index
• C. Composite
• D. Linked key

Explanation: A secondary key is made on a field that you would like to be indexed for faster searches. A table can have more than one secondary key.

• A. Relationship
• B. Cardinality
• C. Modality
• D. Attribute

Explanation: An attribute is a property or characteristic of an object. In a database, attributes are used to define the columns in a table.

• A. One-to-one
• B. One-to-many
• C. Many-to-many
• D. Many-to-one

Explanation: A single book can be read by many different people (many). Likewise, a single person can read many different books (many).

• A. Query
• B. Table
• C. Form
• D. Report

Explanation: A table is the fundamental structure of a relational database. It stores data in a grid-like format with rows and columns.

• A. Each relation name is distinct from the names of other relations in the schema
• B. Tuples in a relation are ordered
• C. None of the other options
• D. Each value in a tuple is atomic
• E. Values of a specific attribute arefrom the same atomic domain

Explanation: Unlike sets, order does not matter in relations. Tuples can be returned or processed in any order without affecting the results

• A. Table
• B. Record
• C. Field
• D. Cell

Explanation: In a relational database table, columns represent categories of data. Each column holds a specific type of information about the entities…