SQL Learning Quizzes: Master Data Manipulation and Retrieval

Question 1

Which of the provided options is NOT a valid condition for a WHERE clause?

Accepted Answer

AND (salary > 50000)

Answer

name = 'John'

Answer

age > 30

Answer

NOT (gender = 'male')

Question 2

Which type of join in SQL retrieves all rows from both tables, regardless of matching values?

Accepted Answer

FULL JOIN

Answer

INNER JOIN

Answer

LEFT JOIN

Answer

RIGHT JOIN

Question 3

Which SQL command is used to specify a primary key for a table?

Accepted Answer

PRIMARY KEY

Answer

UNIQUE

Answer

FOREIGN KEY

Answer

NOT NULL

Question 4

Which SQL statement is utilized to remove all rows from a table?

Accepted Answer

TRUNCATE TABLE

Answer

DELETE FROM

Answer

DROP TABLE

Answer

ALTER TABLE

Question 5

Which join type retrieves all rows from the left table and matching rows from the right table?

Accepted Answer

LEFT JOIN

Answer

INNER JOIN

Answer

RIGHT JOIN

Answer

FULL JOIN

Question 6

Which subquery type returns a single value?

Accepted Answer

Scalar subquery

Answer

Inline subquery

Answer

Common table expression (CTE)

Answer

Lateral subquery

Question 7

Which type of index enhances query performance on large tables?

Accepted Answer

Clustered index

Answer

Non-clustered index

Answer

Bitmap index

Answer

Hash index

Question 8

Which of the following SQL clauses is used to filter the results of a query?

Accepted Answer

WHERE

Answer

ORDER BY

Answer

GROUP BY

Answer

HAVING

Question 9

Which of the following SQL statements is used to create a table?

Accepted Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT *

Answer

UPDATE

Question 10

Which of the following SQL constraints is used to ensure that a column contains unique values?

Accepted Answer

PRIMARY KEY

Answer

FOREIGN KEY

Answer

CHECK

Answer

NOT NULL

Question 11

Which of the following SQL clauses is used to group the results of a query?

Accepted Answer

GROUP BY

Answer

WHERE

Answer

ORDER BY

Answer

HAVING

Question 12

Which operator is used in SQL to compare two values for equality?

Accepted Answer

=

Answer

>

Answer

<

Answer

<>

Question 13

Which SQL command is used to retrieve data from a table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 14

Which clause is used to specify conditions for selecting rows from a table in SQL?

Accepted Answer

WHERE

Answer

FROM

Answer

ORDER BY

Answer

GROUP BY

Question 15

In SQL, which function is used to find the maximum value in a set of values?

Accepted Answer

MAX

Answer

MIN

Answer

AVG

Answer

SUM

Question 16

Which SQL command is used to update data in a table?

Accepted Answer

UPDATE

Answer

INSERT

Answer

DELETE

Answer

SELECT

Question 17

In SQL, what is the primary purpose of creating a view, and what are its key benefits?

Accepted Answer

Provides a customized data presentation, enhances security, and potentially improves query performance.

Answer

Creates a new table with a different structure from the original table.

Answer

Stores frequently used queries for faster execution.

Question 18

In SQL, which syntax is used to create a new table?

Accepted Answer

CREATE TABLE [table_name] ([column_name] [data_type] [constraints])

Answer

CREATE DATABASE [table_name] ([column_name] [data_type] [constraints])

Answer

ADD TABLE [table_name] ([column_name] [data_type] [constraints])

Answer

INSERT INTO [table_name] ([column_name]) VALUES ([values])

Question 19

Which SQL statement is used to fetch data from a table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 20

Which clause in SQL is used to filter rows in a result set?

Accepted Answer

WHERE

Answer

HAVING

Answer

ORDER BY

Answer

LIMIT

Question 21

Which SQL statement is used to modify existing data in a table?

Accepted Answer

UPDATE

Answer

INSERT

Answer

SELECT

Answer

DELETE

Question 22

Which SQL statement is used to delete rows from a table?

Accepted Answer

DELETE

Answer

REMOVE

Answer

TRUNCATE

Answer

ERASE

Question 23

Which of the following is not a standard data type supported by SQL?

Accepted Answer

BYTE

Answer

INTEGER

Answer

VARCHAR

Answer

DATETIME

Question 24

What is the primary purpose of utilizing a 'WHERE' clause in an SQL statement?

Accepted Answer

Filter the result set based on a specified condition

Answer

Specify the names of the columns to be retrieved

Answer

Sort the result set based on a specified criteria

Answer

Group the result set based on a specified field

Question 25

What is the correct syntax for defining a primary key constraint in an SQL table?

Accepted Answer

PRIMARY KEY (column_name)

Answer

CONSTRAINT PRIMARY KEY (column_name)

Answer

KEY PRIMARY (column_name)

Answer

UNIQUE PRIMARY KEY (column_name)

Question 26

Which SQL function is used to determine the highest value within a set of values?

Accepted Answer

MAX()

Answer

MIN()

Answer

AVG()

Answer

SUM()

Question 27

What is the primary distinction between a 'LEFT JOIN' and a 'RIGHT JOIN' in SQL?

Accepted Answer

A LEFT JOIN includes all rows from the left table, even if there is no corresponding row in the right table, while a RIGHT JOIN does the opposite.

Answer

A LEFT JOIN includes all rows from the right table, even if there is no corresponding row in the left table, while a RIGHT JOIN does the opposite.

Answer

Both LEFT JOIN and RIGHT JOIN only include rows that have matching values in both tables.

Answer

There is no difference between LEFT JOIN and RIGHT JOIN.

Question 28

Which SQL command is used to establish a new database?

Accepted Answer

CREATE DATABASE database_name

Answer

ADD DATABASE database_name

Answer

NEW DATABASE database_name

Answer

MAKE DATABASE database_name

Question 29

What is the primary purpose of utilizing transactions in SQL?

Accepted Answer

To guarantee that a set of database operations are either fully completed or entirely reversed

Answer

To enhance the efficiency of queries

Answer

To prevent database corruption

Answer

To generate a backup of the database

Question 30

Which SQL command is used to select data from a database table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 31

What is the purpose of a WHERE clause in an SQL query?

Accepted Answer

To filter the results based on a condition

Answer

To sort the results in ascending order

Answer

To group the results by a column

Answer

To limit the number of results returned

Question 32

Which SQL command is used to create a new table?

Accepted Answer

CREATE TABLE

Answer

ALTER TABLE

Answer

DROP TABLE

Answer

SELECT * FROM

Question 33

What is the purpose of an index in an SQL database?

Accepted Answer

To improve the performance of data retrieval queries

Answer

To enforce referential integrity between tables

Answer

To store duplicate data for backup purposes

Answer

To reduce the size of the database file

Question 34

Which SQL keyword is used to group the results of a query?

Accepted Answer

GROUP BY

Answer

ORDER BY

Answer

HAVING

Answer

DISTINCT

Question 35

What is the primary purpose of the 'WHERE' clause in an SQL query?

Accepted Answer

To restrict the result set based on a specified condition

Answer

To define the table from which data is retrieved

Answer

To sort the result set in ascending or descending order

Answer

To perform mathematical operations on the retrieved data

Question 36

Which of the listed symbols is NOT a valid SQL operator?

Accepted Answer

&

Answer

=

Answer

>

Answer

<

Question 37

Can you explain the difference between a primary key and a foreign key in SQL?

Accepted Answer

A primary key uniquely identifies each row in a table, while a foreign key references the primary key of another table.

Answer

A foreign key uniquely identifies each row in a table, while a primary key references the foreign key of another table.

Answer

Both primary keys and foreign keys serve the same purpose and can be used interchangeably.

Answer

Primary keys are used for data retrieval, while foreign keys are used for data manipulation.

Question 38

What is the primary purpose of a JOIN operation in SQL?

Accepted Answer

To combine rows from multiple tables based on a matching column value

Answer

To create a new table containing data from multiple existing tables

Answer

To delete duplicate rows from a table

Answer

To update the values in a table

Question 39

Explain the purpose of an index in SQL.

Accepted Answer

To enhance the speed of data retrieval queries

Answer

To maintain data integrity and enforce constraints

Answer

To minimize the storage space required by the database

Answer

To create a backup of the database

Question 40

Which of the following is an example of a parameterized query in SQL?

Accepted Answer

SELECT * FROM table WHERE id = ?

Answer

SELECT * FROM table WHERE id = 1

Answer

UPDATE table SET name = 'John' WHERE id = 1

Answer

DELETE FROM table WHERE id = 1

Question 41

What is the significance of a transaction in SQL?

Accepted Answer

It ensures the reliability and completeness of data modifications

Answer

It creates a new database

Answer

It backs up the database

Answer

It purges all data from the database

Question 42

What is the primary purpose of the WHERE clause in an SQL query?

Accepted Answer

To filter rows based on specified conditions

Answer

To sort rows in a particular order

Answer

To group rows by common values

Answer

To aggregate data across multiple rows

Question 43

Which SQL data type is most appropriate for storing integers?

Accepted Answer

INT

Answer

VARCHAR

Answer

FLOAT

Answer

DATE

Question 44

Which SQL operator is used to perform a logical "AND" operation?

Accepted Answer

AND

Answer

OR

Answer

NOT

Answer

IN

Question 45

What is the primary function of the GROUP BY clause in an SQL query?

Accepted Answer

To group rows with common values and perform aggregate functions on them

Answer

To sort rows in a particular order

Answer

To filter rows based on specified conditions

Answer

To create a new table from the existing table

Question 46

Which SQL function is used to calculate the average value of a numeric column?

Accepted Answer

AVG

Answer

SUM

Answer

COUNT

Answer

MIN

Question 47

What is a subquery in SQL?

Accepted Answer

A query that is embedded within another query

Answer

A query that is used to create a new table

Answer

A query that is used to update data in a table

Answer

A query that is used to delete data from a table

Question 48

Which SQL command is used to create a new database?

Accepted Answer

CREATE DATABASE

Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT

Question 49

What is the primary function of the ORDER BY clause in an SQL query?

Accepted Answer

To sort rows in a particular order

Answer

To filter rows based on specified conditions

Answer

To group rows with common values

Answer

To aggregate data across multiple rows

Question 50

In SQL, which keyword is utilized to establish a new table?

Accepted Answer

CREATE

Answer

ALTER

Answer

UPDATE

Answer

INSERT

Question 51

In an SQL SELECT statement, what is the primary function of the WHERE clause?

Accepted Answer

Filtering rows based on specified conditions

Answer

Sorting rows in a particular order

Answer

Grouping rows by a designated column

Answer

Deleting rows from a table

Question 52

Which data type in SQL is intended for storing binary data?

Accepted Answer

BLOB

Answer

VARCHAR

Answer

TEXT

Answer

INTEGER

Question 53

Describe the distinction between an INNER JOIN and an OUTER JOIN in SQL.

Accepted Answer

An INNER JOIN retrieves matching rows from both tables, while an OUTER JOIN retrieves all rows from one table and matching rows from the other.

Answer

An OUTER JOIN retrieves matching rows from both tables, while an INNER JOIN retrieves all rows from one table and matching rows from the other.

Answer

An INNER JOIN retrieves all rows from both tables, while an OUTER JOIN retrieves only matching rows.

Answer

There is no distinction between an INNER JOIN and an OUTER JOIN.

Question 54

Which SQL function is used to extract the day of the week from a given date?

Accepted Answer

DAY()

Answer

WEEK()

Answer

MONTH()

Answer

YEAR()

Question 55

What is the primary purpose of a primary key in an SQL table?

Accepted Answer

To uniquely identify each row in the table

Answer

To enforce referential integrity between tables

Answer

To store the maximum value for a column

Answer

To group rows together

Question 56

In an SQL SELECT statement, what is the purpose of the ORDER BY clause?

Accepted Answer

Sorting the query results in ascending or descending order

Answer

Grouping the query results by a specified column

Answer

Filtering the query results based on specified conditions

Answer

Creating a new table from the query results

Question 57

What is the purpose of the SQL GROUP BY clause?

Accepted Answer

Grouping rows together based on a specified column

Answer

Sorting the query results in ascending or descending order

Answer

Filtering the query results based on specified conditions

Answer

Creating a new table from the query results

Question 58

Which of the following is the correct syntax to create a table in SQL named 'Students' with columns 'id', 'name', and 'age'?

Accepted Answer

CREATE TABLE Students (id INT, name VARCHAR(255), age INT)

Answer

CREATE DATABASE Students (id INT, name VARCHAR(255), age INT)

Answer

TABLE Students (id INT, name VARCHAR(255), age INT) CREATE

Answer

CREATE (Students id INT, name VARCHAR(255), age INT)

Question 59

Which SQL command is used to add a new row into a table?

Accepted Answer

INSERT INTO

Answer

ADD TO

Answer

APPEND TO

Answer

CREATE ROW

Question 60

Which of the following is a function used to calculate the average value of a column in SQL?

Accepted Answer

AVG()

Answer

SUM()

Answer

COUNT()

Answer

MIN()

Question 61

Which SQL command is used to remove rows from a table?

Accepted Answer

DELETE FROM

Answer

REMOVE FROM

Answer

ERASE FROM

Answer

TRUNCATE

Question 62

Which subquery type can retrieve data from multiple rows or combine data from multiple tables?

Accepted Answer

Inline view subquery

Answer

Scalar subquery

Answer

Correlated subquery

Answer

Exists subquery

Question 63

Which data type is a sequence of characters enclosed in single quotes?

Accepted Answer

String

Answer

Integer

Answer

Array

Answer

Object

Question 64

What is the primary purpose of the 'SELECT' statement in SQL?

Accepted Answer

To retrieve data from a database

Answer

To create a new database

Answer

To update data in a database

Answer

To delete data from a database