SQL - Queries

Question 1

_______is the clause we use every time we want to query information from a database.

Answer 1

SELECT

SELECT column1, column2
FROM table_name;

Question 2

_______renames a column or table.

Answer 2

AS

SELECT name AS ‘Titles’
FROM movies;

Question 3

_______ return unique values.

Answer 3

DISTINCT

SELECT DISTINCT tools
FROM inventory;

Question 4

_______is a popular command that lets you filter the results of the query based on conditions that you specify.

Answer 4

WHERE

SELECT *
FROM movies
WHERE imdb_rating > 8;

Question 5

_______and _______are special operators.

Answer 5

LIKE, BETWEEN

SELECT *
FROM movies
WHERE name LIKE ‘A%’;

SELECT *
FROM movies
WHERE year BETWEEN 1990 AND 1999;

Question 6

_______ and _______ combines multiple conditions.

Answer 6

AND, OR

SELECT *
FROM movies
WHERE year BETWEEN 1990 AND 1999
AND genre = ‘romance’;

SELECT *
FROM movies
WHERE year > 2014
OR genre = ‘action’;

Question 7

_______ sorts the result.

Answer 7

ORDER BY

SELECT *
FROM movies
ORDER BY name;

Question 8

_______ specifies the maximum number of rows that the query will return.

Answer 8

LIMIT

SELECT *
FROM movies
LIMIT 10;

Question 9

_______ creates different outputs

Answer 9

CASE

SELECT name,
CASE
WHEN imdb_rating > 8 THEN ‘Fantastic’
WHEN imdb_rating > 6 THEN ‘Poorly Received’
ELSE ‘Avoid at All Costs’
END
FROM movies;

Question 10

Find the error in this code:

SELECT name,
CASE
WHEN imdb_rating > 8 THEN ‘Oscar’
WHEN imdb_rating > 7 THEN ‘Good’
WHEN imdb_rating > 6 THEN ‘Fair’
FROM movies;

Answer 10

Missing END statement.

Question 11

IS NULL condition returns true if the field has no value. T/F?

Answer 11

T

Question 12

How would you query all the unique genres from the ‘books’ table?

Answer 12

SELECT DISTINCT genres
FROM books;

Question 13

What is LIKE?

Answer 13

A special operator that can be used with the WHERE clause to search for a pattern.

Question 14

What does the wildcard character % in the following SQL statement do?

SELECT *
FROM sports
WHERE name LIKE ‘%ball’;

Answer 14

It matches all sports that end with ‘ball’.

Question 15

What is the correct syntax to query both the name and date columns from the database?

SELECT __________
FROM album;

Answer 15

name, date

Question 16

What code would you add to this query to place the colors in reverse alphabetical order (Z to A) by name?

SELECT *
FROM colors
_________________;

Answer 16

ORDER BY name DESC

Question 17

What is ORDER BY?

Answer 17

A clause that sorts the result set alphabetically or numerically.

Question 18

What is LIMIT?

Answer 18

A clause that lets you specify the maximum number of rows the result set will have.

Question 19

Which of the following is NOT a comparison operator in SQL?

!=

> =

~

<

Answer 19

~

Question 20

Quiz: Queries
Which operator would you use to query values that meet all conditions in a WHERE clause?

Answer 20

AND

Question 21

What is the correct query to select only the cities with temperatures less than 35?

SELECT *
FROM cities;

SELECT *
FROM cities
WHERE temperature != 35;

SELECT *
FROM cities
WHERE temperature = 35;

SELECT *
FROM cities
WHERE temperature < 35;

Answer 21

SELECT *
FROM cities
WHERE temperature < 35;