SQL and Database Programming Quizzes - Test Your Skills

Question 1

In SQL, which command is used to create a new table with its columns and data types?

Accepted Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT *

Answer

UPDATE

Question 2

Which SQL statement is used to remove a specific row from a table based on a given condition?

Accepted Answer

DELETE FROM table_name WHERE condition;

Answer

UPDATE table_name SET column_name = NULL WHERE condition;

Answer

DROP TABLE table_name;

Answer

ALTER TABLE table_name DROP COLUMN column_name;

Question 3

In SQL, which constraint prevents a column from accepting null values?

Accepted Answer

NOT NULL

Answer

PRIMARY KEY

Answer

UNIQUE

Answer

DEFAULT

Question 4

Which data type is not natively supported by SQL?

Accepted Answer

Array

Answer

Integer

Answer

String

Answer

Boolean

Question 5

To add a new column to an existing table, which SQL statement should you use?

Accepted Answer

ALTER TABLE table_name ADD COLUMN new_column_name data_type

Answer

CREATE COLUMN new_column_name data_type IN table_name

Answer

UPDATE table_name SET new_column_name = default_value

Question 6

Which SQL statement is used to fetch specific data from a table based on a specified condition?

Accepted Answer

SELECT column1, column2 FROM table_name WHERE condition

Answer

INSERT INTO table_name (column1, column2) VALUES (value1, value2)

Answer

UPDATE table_name SET column1 = value1 WHERE condition

Answer

DELETE FROM table_name WHERE condition

Question 7

Which SQL statement creates a foreign key constraint?

Accepted Answer

ALTER TABLE table_name ADD FOREIGN KEY (column_name) REFERENCES referenced_table_name (column_name)

Answer

CREATE FOREIGN KEY (column_name) REFERENCES referenced_table_name (column_name) ON table_name

Answer

ADD FOREIGN KEY (column_name) ON table_name REFERENCES referenced_table_name (column_name)

Answer

REFERENCES (column_name) ON table_name FOREIGN KEY (column_name) referenced_table_name

Question 8

In SQL, which command is used to create a new database?

Accepted Answer

CREATE DATABASE

Answer

NEW DATABASE

Answer

MAKE DATABASE

Answer

ADD DATABASE

Question 9

Which data type is **not** part of the SQL standard?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

CHAR

Answer

FLOAT

Question 10

In SQL, which command combines data from multiple tables based on a shared column?

Accepted Answer

JOIN

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 11

In SQL, which command creates a new database?

Accepted Answer

CREATE DATABASE

Answer

ADD DATABASE

Answer

NEW DATABASE

Answer

MAKE DATABASE

Question 12

In an SQL query, which clause determines the sequence in which rows are displayed?

Accepted Answer

ORDER BY

Answer

SELECT

Answer

WHERE

Answer

GROUP BY

Question 13

In SQL, which command creates a new database named 'student_db'?

Accepted Answer

CREATE DATABASE student_db;

Answer

MAKE DATABASE student_db;

Answer

NEW DATABASE student_db;

Answer

CREATE TABLE student_db;

Question 14

Which SQL statement creates a new database?

Accepted Answer

CREATE DATABASE database_name

Answer

SELECT * FROM database_name

Answer

INSERT INTO database_name VALUES (data)

Answer

DROP DATABASE database_name

Question 15

Which SQL statement correctly creates a new view named `customer_view` that includes all columns from the `customer` table?

Accepted Answer

CREATE VIEW customer_view AS SELECT * FROM customer;

Answer

ALTER TABLE customer CREATE VIEW customer_view AS SELECT * FROM customer;

Answer

SELECT * FROM customer INTO customer_view;

Answer

CREATE TABLE customer_view AS SELECT * FROM customer;

Question 16

In SQL, which operator can be used to combine multiple conditions in a WHERE clause, returning rows that meet all the specified conditions?

Accepted Answer

AND

Answer

NOT

Answer

OR

Answer

XOR

Question 17

Which SQL statement permanently removes duplicate records from a table, ensuring distinctness based on specific column(s)?

Accepted Answer

DELETE ... WHERE ROW_NUMBER() OVER (PARTITION BY ... ORDER BY ...) > 1

Answer

CREATE UNIQUE INDEX

Answer

ALTER TABLE ... ADD UNIQUE

Answer

TRUNCATE TABLE

Question 18

Which SQL statement retrieves all rows from Table1 and their corresponding address from Table2?

Accepted Answer

SELECT * FROM Table1 INNER JOIN Table2 ON Table1.id = Table2.id

Answer

SELECT * FROM Table1, Table2 WHERE Table1.id = Table2.id

Answer

SELECT * FROM Table1 UNION SELECT * FROM Table2

Answer

SELECT * FROM Table1 EXCEPT SELECT * FROM Table2

Question 19

Which SQL statement is used to establish a new view?

Accepted Answer

CREATE VIEW

Answer

CREATE TABLE

Answer

SELECT * FROM

Answer

INSERT INTO

Question 20

Which SQL statement is used to retrieve data from a table based on specific conditions?

Accepted Answer

SELECT

Answer

CREATE TABLE

Answer

INSERT INTO

Answer

UPDATE

Question 21

Which SQL statement retrieves the first 5 rows from the 'customers' table?

Accepted Answer

SELECT * FROM customers LIMIT 5;

Answer

SELECT 5 FROM customers;

Answer

GET 5 customers;

Answer

SELECT TOP 5 * FROM customers;

Question 22

Which SQL statement correctly creates a table named "Customers" with three columns: `id` (primary key), `name` (string), and `age` (integer)?

Accepted Answer

CREATE TABLE Customers (id INT PRIMARY KEY, name VARCHAR(255), age INT)

Answer

CREATE TABLE Customers (id INT PRIMARY, name VARCHAR(255), age INT)

Answer

CREATE TABLE Customers (id INT PRIMARY KEY, name CHAR(255), age INT)

Answer

ADD TABLE Customers (id INT PRIMARY KEY, name VARCHAR(255), age INT)

Question 23

In SQL, which command creates a new database?

Accepted Answer

CREATE DATABASE

Answer

NEW DATABASE

Answer

MAKE DATABASE

Answer

ADD DATABASE

Question 24

In the Employees table, which SQL statement would prevent duplicate department names from being entered?

Accepted Answer

ALTER TABLE Employees ADD CONSTRAINT department_unique UNIQUE (department);

Answer

ALTER TABLE Employees ADD CONSTRAINT department_primary_key PRIMARY KEY (department);

Answer

ALTER TABLE Employees ADD CONSTRAINT department_not_null NOT NULL (department);

Answer

ALTER TABLE Employees ADD CONSTRAINT department_foreign_key FOREIGN KEY (department) REFERENCES Departments (department_id);

Question 25

Which SQL command enables you to modify the structure of an existing table by adding, removing, or altering columns?

Accepted Answer

ALTER

Answer

CREATE

Answer

INSERT

Answer

UPDATE

Question 26

Which data type is NOT supported by SQL?

Accepted Answer

OBJECT

Answer

INTEGER

Answer

CHARACTER VARYING

Answer

DATETIME

Question 27

Which SQL statement retrieves all rows from the 'Orders' table where the 'order_date' is after January 1st, 2023?

Accepted Answer

SELECT * FROM Orders WHERE order_date > '2023-01-01'

Answer

GET * FROM Orders WHERE order_date > '2023-01-01'

Answer

SELECT * FROM Orders > '2023-01-01'

Answer

ORDER BY * FROM Orders WHERE order_date > '2023-01-01'

Question 28

In SQL, which keyword is used to indicate the table(s) from which data should be retrieved?

Accepted Answer

FROM

Answer

SELECT

Answer

WHERE

Answer

TABLE

Question 29

In SQL, which command is used to grant database permissions to users or groups, allowing them to access and modify database objects like tables and views?

Accepted Answer

GRANT

Answer

REVOKE

Answer

CREATE USER

Question 30

Which SQL statement is used to create a database named 'my_database'?

Accepted Answer

CREATE DATABASE my_database;

Answer

CREATE TABLE my_database;

Answer

DROP DATABASE my_database;

Answer

ALTER DATABASE my_database;

Question 31

Which SQL statement combines rows from multiple tables based on a shared value in a specified column?

Accepted Answer

SELECT * FROM table1 INNER JOIN table2 ON table1.column1 = table2.column2

Answer

SELECT * FROM table1, table2 WHERE table1.column1 = table2.column2

Answer

SELECT * FROM table1 LEFT JOIN table2 ON table1.column1 = table2.column2

Answer

SELECT * FROM table1 FULL JOIN table2 ON table1.column1 = table2.column2

Question 32

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

Accepted Answer

SELECT

Answer

CREATE TABLE

Answer

INSERT

Answer

UPDATE

Question 33

Which SQL statement creates a new database called "my_database"?

Accepted Answer

CREATE DATABASE "my_database"

Answer

CREATE TABLE "my_database"

Answer

USE "my_database"

Answer

DROP DATABASE "my_database"

Question 34

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

Accepted Answer

Object

Answer

Integer

Answer

String

Answer

Boolean

Question 35

Which of the following is a disadvantage of using stored procedures in database programming?

Accepted Answer

Increased development time

Answer

Encapsulation of complex SQL statements

Answer

Improved performance

Answer

Increased security

Question 36

In SQL, create a view called 'customer_view' that displays all columns from the 'customer' table and calculates the total number of orders placed by each customer.

Accepted Answer

CREATE VIEW customer_view AS SELECT *, COUNT(*) AS total_orders FROM customer GROUP BY customer_id;

Answer

CREATE VIEW customer_view AS SELECT * FROM customer;

Answer

CREATE VIEW customer_view AS SELECT customer_id, COUNT(*) FROM customer GROUP BY customer_id;

Answer

CREATE VIEW customer_view AS SELECT * FROM customer JOIN orders ON customer.customer_id = orders.customer_id;

Question 37

Which of the following is NOT a recognized SQL data type?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

VARCHAR

Answer

BOOLEAN

Question 38

In SQL, what is the purpose of the 'SELECT' command?

Accepted Answer

Retrieving data from a table

Answer

Inserting data into a table

Answer

Updating data in a table

Answer

Deleting data from a table

Question 39

Which syntax is correct for creating a table in SQL?

Accepted Answer

CREATE TABLE table_name (column_name data_type);

Answer

CREATE TABLE table_name column_name data_type;

Answer

CREATE table_name (column_name data_type);

Answer

CREATE table_name column_name data_type;

Question 40

What is the defining difference between a stored procedure and a function in SQL?

Accepted Answer

Stored procedures can alter data, while functions cannot.

Answer

Stored procedures can't return values, whereas functions can.

Answer

Functions cannot accept parameters, but stored procedures can.

Answer

Stored procedures and functions are essentially the same.

Question 41

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

Accepted Answer

=

Answer

>

Answer

<

Answer

!=

Question 42

Which SQL statement would you use to create a database trigger that automatically updates the 'last_login' column in the 'Users' table whenever a user successfully logs into the system?

Accepted Answer

CREATE TRIGGER log_login ON Logins AFTER INSERT AS UPDATE Users SET last_login = GETDATE() WHERE user_id = NEW.id

Answer

CREATE TRIGGER log_login ON Users AFTER INSERT AS UPDATE Users SET last_login = GETDATE() WHERE id = NEW.id

Answer

CREATE TRIGGER log_login ON Users AFTER UPDATE AS UPDATE Users SET last_login = GETDATE() WHERE id = NEW.id

Answer

CREATE TRIGGER log_login ON Logins AFTER DELETE AS UPDATE Users SET last_login = GETDATE() WHERE id = NEW.id

Question 43

Which SQL statement type is used to retrieve data from multiple tables, combining rows based on shared attributes?

Accepted Answer

JOIN

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 44

Which of the following is NOT a valid SQL data type?

Accepted Answer

OBJECT

Answer

INT

Answer

VARCHAR

Answer

DECIMAL

Question 45

What is the primary purpose of an SQL WHERE clause?

Accepted Answer

To filter rows in a table based on a specified condition

Answer

To create a new table with filtered data

Answer

To update rows in a table based on a condition

Answer

To delete rows from a table that meet a condition

Question 46

What is the primary function of a database trigger?

Accepted Answer

To automatically execute a set of actions when a specified event occurs in the database

Answer

To improve database performance by optimizing queries

Answer

To ensure data integrity by enforcing constraints

Answer

To create a backup of the database

Question 47

Which of the following is NOT a component of a relational database management system (RDBMS)?

Accepted Answer

Web application server

Answer

Database engine

Answer

Query optimizer

Answer

Transaction manager

Question 48

What is the key distinction between a primary key and a foreign key?

Accepted Answer

A primary key uniquely identifies a row in a table, while a foreign key references a primary key in another table

Answer

A primary key can be a composite of multiple columns, while a foreign key must be a single column

Answer

A foreign key can only reference a primary key in the same table, while a primary key can reference a foreign key in another table

Answer

There is no difference between a primary key and a foreign key

Question 49

What is the primary purpose of a database index?

Accepted Answer

To speed up the retrieval of data from a table

Answer

To ensure the uniqueness of data in a table

Answer

To protect the data in a table from unauthorized access

Answer

To compress the data in a table

Question 50

In SQL, which command is used to create a new database?

Accepted Answer

CREATE DATABASE

Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT * FROM

Question 51

In SQL, the syntax to create a table is:

Accepted Answer

CREATE TABLE <table_name> (column_name data_type, ...);

Answer

MAKE TABLE <table_name> (column_name data_type, ...);

Answer

DEFINE TABLE <table_name> (column_name data_type, ...);

Answer

BUILD TABLE <table_name> (column_name data_type, ...);

Question 52

In SQL, which operator is used to compare values for equality?

Accepted Answer

=

Answer

==

Answer

EQ

Answer

IS

Question 53

In C programming, which syntax is used to execute an embedded SQL statement?

Accepted Answer

exec sql statement;

Answer

sql statement;

Answer

execute statement;

Answer

call statement;

Question 54

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 ensure all rows in the table are unique

Answer

To store the most critical data in the table

Answer

To improve the efficiency of queries

Question 55

What is a transaction in the context of SQL?

Accepted Answer

A series of database operations treated as a single unit

Answer

A temporary storage area for data in memory

Answer

An index structure used to enhance query performance

Answer

A function that can be invoked within SQL statements

Question 56

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

Accepted Answer

To enforce referential integrity between tables

Answer

To uniquely identify each row in a table

Answer

To store the most critical data in a table

Answer

To improve the efficiency of queries

Question 57

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

Accepted Answer

To filter the results of the query

Answer

To group the results of the query

Answer

To order the results of the query

Answer

To limit the results of the query

Question 58

Which practice is essential for safeguarding database security?

Accepted Answer

Enforcing robust access controls and encrypting sensitive data

Answer

Granting unrestricted database access to all users

Answer

Using weak passwords and neglecting password expiration policies

Question 59

What is a unique feature of the network database model that sets it apart from the hierarchical database model?

Accepted Answer

Each child can have multiple parents.

Answer

Data is organized in a tree-like structure.

Answer

The model is suitable for representing data with inherent hierarchical relationships.

Answer

The model supports efficient navigation of data.

Question 60

Which SQL statement is used to create a new table?

Accepted Answer

CREATE TABLE table_name (column_name data_type, ...)

Answer

SELECT * FROM table_name

Answer

INSERT INTO table_name (column_name, ...) VALUES (...)

Answer

UPDATE table_name SET column_name = value, ...

Question 61

What is the primary purpose of a primary key in a database table?

Accepted Answer

To ensure that each row in the table is unique.

Answer

To identify the relationship between rows in different tables.

Answer

To store the data values for a specific column.

Answer

To enforce data integrity constraints.

Question 62

Which of the following is a valid SQL data type for storing dates?

Accepted Answer

DATE

Answer

VARCHAR

Answer

INT

Answer

CHAR

Question 63

How does a subquery differ from a joined query?

Accepted Answer

A subquery is a query nested within another query, while a joined query combines data from multiple tables.

Answer

A joined query is a query nested within another query, while a subquery combines data from multiple tables.

Answer

There is no difference between a subquery and a joined query.

Answer

A subquery combines data from multiple tables, while a joined query is a query nested within another query.

Question 64

What is the function of the COMMIT statement in SQL?

Accepted Answer

To permanently save changes made to the database

Answer

To cancel changes made to the database

Answer

To create a checkpoint in the database

Answer

To rollback changes made to the database