SQL

Question 1

What does SQL stand for?

Answer 1

Structured Query Language

Question 2

True or False: SQL is used to communicate with databases.

Answer 2

True

Question 3

Fill in the blank: The command used to retrieve data from a database is called _____ .

Answer 3

SELECT

Question 4

What is the purpose of the WHERE clause in SQL?

Answer 4

To filter records based on specified conditions.

Question 5

Which SQL command is used to add new records to a database?

Answer 5

INSERT

Question 6

True or False: The SQL command UPDATE is used to delete records from a database.

Answer 6

False

Question 7

What is the primary key in a database?

Answer 7

A unique identifier for each record in a table.

Question 8

What does the GROUP BY clause do in SQL?

Answer 8

It groups rows that have the same values in specified columns into summary rows.

Question 9

Which SQL keyword is used to sort the result set?

Answer 9

ORDER BY

Question 10

What is a foreign key?

Answer 10

A field in one table that uniquely identifies a row of another table.

Question 11

Fill in the blank: The SQL command used to remove records from a table is _____ .

Answer 11

DELETE

Question 12

What is the purpose of the JOIN clause in SQL?

Answer 12

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

Question 13

Which SQL command is used to modify existing records in a database?

Answer 13

UPDATE

Question 14

True or False: The DISTINCT keyword is used to return only unique values.

Answer 14

True

Question 15

What does the COUNT function do in SQL?

Answer 15

Returns the number of rows that match a specified criterion.

Question 16

What is normalization in database design?

Answer 16

The process of organizing data to reduce redundancy and improve data integrity.

Question 17

What is the function of the HAVING clause?

Answer 17

To filter records after an aggregation has been performed.

Question 18

Fill in the blank: In SQL, the _____ command is used to create a new table.

Answer 18

CREATE TABLE

Question 19

What is a subquery?

Answer 19

A query nested inside another query.

Question 20

True or False: SQL is a case-sensitive language.

Answer 20

False

Question 21

What does the term ‘data type’ refer to in SQL?

Answer 21

A classification that specifies which type of value a column can hold.

Question 22

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

Answer 22

MAX()

Question 23

What is a view in SQL?

Answer 23

A virtual table based on the result of a SELECT query.

Question 24

Fill in the blank: The SQL command to change the structure of an existing table is _____ .

Answer 24

ALTER TABLE

Question 25

What is the purpose of the LIMIT clause in SQL?

Answer 25

To specify the maximum number of records to return.

Question 26

Which SQL command is used to define a new database?

Answer 26

CREATE DATABASE

Question 27

What does the term ‘transaction’ mean in SQL?

Answer 27

A sequence of operations performed as a single logical unit of work.