SQL Syntax, Commands, and Functions: Master Data Manipulation and Retrieval

Question 1

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

Accepted Answer

INSERT INTO

Answer

APPEND

Answer

ADD ROW

Answer

PUSH

Question 2

In a SELECT statement, what is the purpose of the WHERE clause?

Accepted Answer

To filter the resulting rows based on a specified condition

Answer

To sort the resulting rows in ascending or descending order

Answer

To group the resulting rows by a specified column

Answer

To limit the number of rows returned

Question 3

Which SQL aggregate function calculates the sum of values in a specified column?

Accepted Answer

SUM

Answer

AVG

Answer

COUNT

Answer

MAX

Question 4

What is a primary benefit of using an index in SQL?

Accepted Answer

Faster data retrieval by organizing data in a specific order

Answer

Enforcement of data integrity by ensuring unique values in certain fields

Answer

Limitation of the number of rows returned by a query

Answer

Establishment of relationships between tables

Question 5

Which operator is NOT used for comparison in SQL?

Accepted Answer

<>

Answer

=

Answer

>

Answer

<

Question 6

Which practice is recommended for writing efficient SQL queries?

Accepted Answer

Utilizing indexes where applicable

Answer

Avoiding the use of subqueries

Answer

Using wildcard characters (*) to select all columns

Answer

Delaying query optimization until performance issues arise

Question 7

Which SQL statement is used to select only certain columns from a table?

Accepted Answer

SELECT column1, column2 FROM table_name

Answer

SELECT * FROM table_name

Answer

WHERE column_name = value FROM table_name

Question 8

Which SQL statement is used to modify the structure of an existing table, such as adding or removing columns?

Accepted Answer

ALTER TABLE

Answer

CREATE TABLE

Answer

UPDATE

Question 9

Which SQL statement is used to retrieve data from a database?

Accepted Answer

SELECT

Answer

CREATE TABLE

Answer

UPDATE

Answer

DELETE

Question 10

Which data type is **not** supported in SQL?

Accepted Answer

Array

Answer

Integer

Answer

String

Answer

Boolean

Question 11

Which data type is NOT a fundamental type in SQL?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

CHARACTER

Answer

FLOAT

Question 12

Which of the following data types is NOT natively supported in SQL?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

BOOLEAN

Answer

STRING

Question 13

Which of the following SQL statements is used specifically to retrieve data from a database?

Accepted Answer

SELECT * FROM table_name

Answer

CREATE TABLE table_name (column_name data_type)

Answer

UPDATE table_name SET column_name = new_value

Question 14

Which SQL command is primarily used to retrieve data from a database?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 15

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

Accepted Answer

To filter the returned data based on specified conditions

Answer

To create a new table

Answer

To insert data into a table

Question 16

Which SQL data type is specifically designed to store dates and times?

Accepted Answer

TIMESTAMP

Answer

VARCHAR

Answer

INT

Answer

BOOLEAN

Question 17

What is the primary function of an 'INNER JOIN' in SQL?

Accepted Answer

To combine rows from two tables based on a common column value

Answer

To create a new table

Answer

To update data in a table

Question 18

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

Accepted Answer

AVG()

Answer

COUNT()

Answer

MAX()

Answer

SUM()

Question 19

What is the key 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 a primary key in another table, establishing a relationship between them

Answer

Both are used to create relationships between tables

Question 20

What is the primary purpose of an 'INDEX' in SQL?

Accepted Answer

To enhance query performance by enabling faster data retrieval based on specified columns

Answer

To create a new table

Answer

To update data in a table

Question 21

Which SQL statement is used to establish a new database?

Accepted Answer

CREATE DATABASE <database_name>

Answer

SELECT * FROM <database_name>

Answer

USE <database_name>

Question 22

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

Accepted Answer

To sort the retrieved data in ascending or descending order based on specified columns

Answer

To filter the returned data

Answer

To group the returned data

Question 23

Which of the following is the correct syntax to create a table named 'Students' with columns 'ID', 'Name', and 'Age'?

Accepted Answer

CREATE TABLE Students (ID INT PRIMARY KEY, Name VARCHAR(255) NOT NULL, Age INT NOT NULL)

Answer

CREATE TABLE Students (ID VARCHAR(255), Name INT, Age VARCHAR(255))

Answer

CREATE TABLE Students (ID INT, Name VARCHAR(255), Age INT, PRIMARY KEY (ID))

Question 24

Which SQL statement is used to retrieve all rows from the 'Students' table?

Accepted Answer

SELECT * FROM Students

Answer

READ * FROM Students

Answer

PULL ALL Students

Answer

GET Students

Question 25

Which of the following operators is used to compare two values in an SQL WHERE clause?

Accepted Answer

=

Answer

+

Answer

*

Answer

-

Question 26

What is the purpose of the 'JOIN' statement in SQL?

Accepted Answer

To combine rows from two or more tables based on a shared column

Answer

To delete rows from a table

Answer

To create a new table

Question 27

Which SQL function is used to find the maximum value in a column?

Accepted Answer

MAX()

Answer

AVG()

Answer

MIN()

Answer

SUM()

Question 28

What is the purpose of an SQL 'PRIMARY KEY' constraint?

Accepted Answer

To ensure that each row in a table has a unique identifier

Answer

To enforce a specific data type for a column

Answer

To prevent duplicate rows in a table

Question 29

What is the difference between an 'INNER JOIN' and an 'OUTER JOIN' in SQL?

Accepted Answer

An INNER JOIN returns matching rows from multiple tables, while an OUTER JOIN includes all rows from one or more tables, even if there are no matching values

Answer

An INNER JOIN is used to combine tables, while an OUTER JOIN is used to create new tables

Question 30

What is the purpose of the 'ORDER BY' clause in an SQL statement?

Accepted Answer

To sort the results of a query based on specified column(s) in ascending or descending order

Answer

To group the results of a query

Answer

To filter the results of a query

Question 31

Which of the following is the correct syntax to create a table named 'Customers' with columns 'CustomerID' (INT), 'CustomerName' (VARCHAR(255)), and 'ContactNumber' (VARCHAR(255))?

Accepted Answer

CREATE TABLE Customers (CustomerID INT, CustomerName VARCHAR(255), ContactNumber VARCHAR(255))

Answer

Customers (CustomerID INT, CustomerName VARCHAR(255), ContactNumber VARCHAR(255))

Answer

CREATE TABLE Customers(CustomerID INT, CustomerName VARCHAR(255), ContactNumber VARCHAR(255))

Answer

CREATE Customers (CustomerID INT, CustomerName VARCHAR(255), ContactNumber VARCHAR(255))

Question 32

Which command is used to retrieve all rows and columns from the 'Products' table?

Accepted Answer

SELECT * FROM Products

Answer

SHOW Products

Answer

READ Products

Answer

GET Products

Question 33

Which function is used to count the number of distinct values in a column?

Accepted Answer

COUNT(DISTINCT column_name)

Answer

COUNT(ALL column_name)

Answer

COUNT(column_name)

Answer

COUNT(*) OVER ()

Question 34

Which of the following is a data type used to store dates and times in SQL?

Accepted Answer

TIMESTAMP

Answer

INTEGER

Answer

FLOAT

Answer

STRING

Question 35

Which of the following joins retrieves rows from two tables based on a common column between them and returns only the matching rows?

Accepted Answer

INNER JOIN

Answer

RIGHT JOIN

Answer

FULL JOIN

Answer

LEFT JOIN

Question 36

Which clause is used to specify the sort order of the results returned by a query?

Accepted Answer

ORDER BY

Answer

HAVING

Answer

LIMIT

Answer

GROUP BY

Question 37

Which of the following is a graphical representation of a database schema?

Accepted Answer

Entity-relationship diagram (ERD)

Answer

Class diagram

Answer

Use case diagram

Answer

Flowchart

Question 38

Which command is used to permanently remove a table from the database?

Accepted Answer

DROP TABLE

Answer

REMOVE TABLE

Answer

TRUNCATE

Answer

DELETE FROM

Question 39

Which SQL command is used to construct a new table within a database?

Accepted Answer

CREATE TABLE

Answer

ALTER TABLE

Answer

INSERT INTO

Answer

DROP TABLE

Question 40

Which SQL command is utilized to retrieve data from a specified table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 41

Which of the following SQL operators is used to determine the equality of two provided values?

Accepted Answer

=

Answer

/

Answer

+

Answer

-

Question 42

Which SQL function is employed to identify the maximum value within a dataset?

Accepted Answer

MAX()

Answer

MIN()

Answer

COUNT()

Answer

AVG()

Question 43

Which SQL keyword is used to establish a foreign key constraint?

Accepted Answer

FOREIGN KEY

Answer

UNIQUE

Answer

PRIMARY KEY

Answer

NOT NULL

Question 44

Which SQL statement is used to modify the structure of an existing table?

Accepted Answer

ALTER TABLE

Answer

SELECT * FROM

Answer

DROP TABLE

Answer

CREATE TABLE

Question 45

Which of the following SQL data types is used for storing binary data in a database?

Accepted Answer

BLOB

Answer

DATE

Answer

VARCHAR

Answer

INTEGER

Question 46

Which SQL command is utilized to insert data into a table?

Accepted Answer

INSERT INTO

Answer

UPDATE

Answer

DELETE

Answer

SELECT

Question 47

Which SQL clause is used to specify the criteria for filtering data during retrieval?

Accepted Answer

WHERE

Answer

SELECT

Answer

FROM

Question 48

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

Accepted Answer

SELECT

Answer

EXTRACT

Answer

FETCH

Answer

GET

Question 49

What does the acronym SQL stand for?

Accepted Answer

Structured Query Language

Answer

Simple Query Language

Answer

Standard Query Logic

Answer

System Query Language

Question 50

Which SQL clause is used to filter data based on specific conditions?

Accepted Answer

WHERE

Answer

CONDITION

Answer

FILTER

Answer

IF

Question 51

What is the purpose of the PRIMARY KEY constraint in a SQL table?

Accepted Answer

To uniquely identify each row in a table

Answer

To establish a relationship between tables

Answer

To define the data type of a column

Answer

To specify default values for a column

Question 52

Which SQL command is used to create a new table in a database?

Accepted Answer

CREATE TABLE

Answer

INSERT TABLE

Answer

MAKE TABLE

Answer

ADD TABLE

Question 53

To combine data from two tables that share a common column, which SQL clause would you use?

Accepted Answer

JOIN

Answer

UNION

Answer

MERGE

Answer

CONNECT

Question 54

What is the function of the SQL command 'ORDER BY'?

Accepted Answer

To sort the retrieved data in a specific order

Answer

To filter data based on a condition

Answer

To group rows with the same values

Answer

To update existing data in a table

Question 55

Which SQL function calculates the average value of a numeric column?

Accepted Answer

AVG()

Answer

CALCULATE_AVG()

Answer

MEAN()

Answer

AVERAGE()

Question 56

What is the main benefit of using aliases in SQL queries?

Accepted Answer

To improve readability and provide shorter names for tables or columns

Answer

To perform mathematical calculations on data

Answer

To create temporary tables for storing intermediate results

Question 57

Which SQL statement is used to change existing data within a database table?

Accepted Answer

UPDATE

Answer

CHANGE

Answer

ALTER

Answer

MODIFY