SQL and Relational Databases 101 Cognitive Class Exam Quiz Answers

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SQL and Relational Databases 101 Cognitive Class Certification Answers

Module 1 – SQL and Relational Databases 101 Quiz Answers – Cognitive Class

Question 1: What is a Database?

A program that stores data
Stores data in tabular form
A repository of data
All of the above

Question 2: Advantages of the relational model include:

Provides logical and physical data independence
Data is stored in simple data structures
It is the most used data model
All of the above

Question 3: In an Entity-Relationship diagram, the Entity Name maps to the Table name, the attributes map to the …

Table rows and columns
Table columns
Table rows
None of the above

Module 2 – Relational Model Constraints and Data Objects Quiz Answers – Cognitive Class

Question 1: Which of the following statements is true?

A table can have a primary key and a foreign key
A Foreign Key is a set of columns referring to a primary key of another table
A primary key uniquely identifies each row in a table
All of the above

Question 2: Which Relational Constraint prevents duplicate values in a table?

Entity Integrity constraint
Null constraint
Check constraint
All of the above

Question 3: The Semantic Integrity Constraint defines the relationships between tables. (T/F)

True
False

Module 3 – Data Definition Language (DDL) and Data Manipulation Language (DML) Quiz Answers – Cognitive Class

Question 1: The Primary Key of a relational table uniquely identifies each _____ in a table.

column
row
Both of the above
Neither of the above

Question 2: The INSERT statement cannot be used to insert multiple rows in a single statement. (T/F)

True
False

Question 3: The SELECT statement is called a Query, and the output we get from executing the query is called a Result Set. (T/F)

True
False

Module 4 – Advanced DDL and DML Quiz Answers – Cognitive Class

Question 1: You want to select an author’s name from a table, but you only remember the author’s last name starts with the letter B, which string pattern can you use?

SELECT lastname from author where lastname like ‘B$’
SELECT lastname from author where lastname like ‘B%’
SELECT lastname from author where lastname like ‘B#’
None of the above

Question 2: In a SELECT statement, which SQL clause controls how the result set is displayed?

ORDER BY clause
ORDER IN clause
ORDER WITH clause

Question 3: Which SELECT statement eliminates duplicates in the result set?

SELECT country from author ORDER BY 1
SELECT distinct(country) from author
SELECT unique(country) from author
None of the above

Module 5 – Working with Multiple Tables Quiz Answers – Cognitive Class

Question 1: An INNER JOIN returns only the rows that match. (T/F)

True
False

Question 2: A LEFT OUTER JOIN displays all the rows from the right table, and combines matching rows from the left table. (T/F)

True
False

Question 3: When using an OUTER JOIN, you must explicitly state that you want either a LEFT JOIN or a RIGHT JOIN. (T/F)

True
False

SQL and Relational Databases 101 Final Exam Answers – Cognitive Class

Question 1: The 5 basic SQL commands are…

CREATE, SELECT, INSERT, UPDATE, DELETE
CREATE, ALTER, INSERT, UPDATE, DELETE
CREATE, SELECT, INSERT, MODIFY, DELETE
All of the above

Question 2: The blueprint of any database system is the …

Data model
Information model
Both of the above

Question 3: Attributes help clarify relationship diagrams (T/F)

True
False

Question 4: A table containing one or more foreign keys is called a Parent table. (T/F)

True
False

Question 5: The Referential Integrity Constraint ensures the validity of the data using a combination of Primary Keys and Foreign Keys.

True
False

Question 6: What are the basic categories of the SQL language based on functionality?

Data Manipulation Language
Data Definition Language
Both of the above
Neither of the above

Question 7: The CREATE TABLE statement is a….

DDL statement
DML statement
Both of the above

Question 8: When using the UPDATE statement, if you do not specify the WHERE clause, all the rows in the table are updated.

True
False

Question 9: You want to select a list of books whose number of pages is between 100 and 200 . Select the correct query from the following options.

SELECT title, pages from book where pages BETWEEN 100 AND 200
SELECT title, pages from book where pages RANGE 100 AND 200
SELECT title, pages from book where pages less than or equal to 100 AND pages greater than or equal to 200
A or B
All the options above are correct

Question 10: What is the default sorting mode of the ORDER BY clause?

Ascending
Descending
Randomly selected order
None of the above
All of the above

Question 11: Which of the following can be used in a SELECT statement to restrict a result set?

HAVING
GROUP BY
DISTINCT
All of the above

Question 12: The HAVING clause works only with the GROUP BY clause. (T/F)

True
False

Question 13: Which of the following are valid types of OUTER JOIN?

LEFT OUTER JOIN
RIGHT OUTER JOIN
FULL OUTER JOIN
A and B only
All of the above

Question 14: A FULL JOIN returns only the rows that match. (T/F)

True
False

Question 15: To combine tables in relational databases, we use:

Table names
Matching values/Primary key
Tables cannot be combined
None of the above options are correct

Question 16: >> True or False: Semantic integrity ensures that data entered into a row reflects an allowable value for that row.

True
False

Question 17: Which of the following statements are correct about databases:

A database represents some aspect of the real world
A database is a logically coherent collection of data with some inherent meaning
A database is designed, built and populated with data for a specific purpose
All the above options are correct

Question 18: Which of the following statements are correct about primary keys

The value of the Primary Key must be unique for each instance of the entity.
There can be no missing values (i.e., Not Null) for Primary Keys.
The Primary Key is immutable .i.e., once created the value of the Primary Key cannot be changed.
All the above options are correct

Question 19: The ____________ keyword is used to eliminate duplicate tuples from the result set of an SQL query.

COMMON
DISTINCT
ALL
EXISTS

Question 20: Select the correct statements about the join operator

Primary Key- Foreign Key is the common join operator
Is used to combine more than one table
You have to know the relationship between the tables
None of the Statements are correct

Introduction to SQL and Relational Databases 101

SQL (Structured Query Language) is a programming language specifically designed for managing and manipulating relational databases. A relational database is a type of database that stores and organizes data into tables, where each table consists of rows and columns. The relationships between tables are defined based on common attributes, enabling efficient data retrieval and management.

Here are some key concepts related to SQL and relational databases:

Tables: In a relational database, data is stored in tables, which are organized into rows and columns. Each row represents a record, and each column represents an attribute or field.
Columns (Fields): Columns define the attributes of a table, specifying the type of data that can be stored in them. Common data types include integers, strings, dates, and more.
Rows (Records): Rows contain the actual data in the table. Each row represents a single record or entry in the database.
Primary Key: A primary key is a unique identifier for each record in a table. It ensures that each row can be uniquely identified, and it is often used to establish relationships between tables.
Foreign Key: A foreign key is a column or set of columns in a table that refers to the primary key of another table. It establishes a link between the two tables, creating a relationship.
Normalization: Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves breaking down large tables into smaller, more manageable ones and establishing relationships between them.
Indexing: Indexes are used to optimize the retrieval of data from a database. They provide a quick lookup mechanism, making queries more efficient.
SQL Statements:
- SELECT: Retrieves data from one or more tables.
- INSERT: Adds new records to a table.
- UPDATE: Modifies existing records in a table.
- DELETE: Removes records from a table.
- CREATE: Creates new tables, indexes, or other database objects.
- ALTER: Modifies the structure of an existing database object.
- DROP: Deletes a database object.
Joins: Joins are used to combine rows from two or more tables based on related columns. Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
Transactions: Transactions ensure the consistency and integrity of a database. They consist of a sequence of one or more SQL statements that are executed as a single unit, either entirely or not at all.

SQL is widely used in database management systems (DBMS) such as MySQL, PostgreSQL, Microsoft SQL Server, Oracle Database, and SQLite, among others. It provides a standardized way to interact with and manage relational databases.