KamiBG

 SELECT * FROM survey
 LIMIT 10;

 -- What is the number of responses for each question?
 SELECT question, COUNT(response) FROM survey
 GROUP BY question;

 -- The questions 3. Which shapes do you like? and 5. When was your last eye exam? have lower completion rates (80% and 75% respectively). A possible reason might be people don't know which shape fits their face and don't remember when was their last eye exam.

 -- Create a new table (structure of the new table is given):

KamiBG

-- How many entries in the countries table are from Africa?
SELECT COUNT(id) FROM countries
WHERE continent = 'Africa';

--What was the total population of the continent of Oceania in 2005?
SELECT SUM(population) FROM population_years
JOIN countries
ON population_years.country_id = countries.id
WHERE population_years.year = 2005 AND countries.continent = 'Oceania';

KamiBG

 SELECT * FROM met
 LIMIT 10;

 -- How many pieces are in the American Decorative Art collection?
 SELECT COUNT(title) FROM met;

 -- Count the number of pieces where the category includes ‘celery’.
 SELECT DISTINCT category, COUNT(category) FROM met
 WHERE category LIKE '%celery%';

KamiBG

 SELECT * FROM hacker_news
 LIMIT 20;

 -- What are the top five stories with the highest scores?
 SELECT title, score FROM hacker_news
 ORDER BY score DESC
 LIMIT 5;

-- Is a small percentage of Hacker News submitters taking the majority of the points?
SELECT user, SUM(score) FROM hacker_news

KamiBG

SELECT * FROM startups;

-- Calculate the total number of companies in the table:
SELECT COUNT(name) FROM startups;

-- Find the total value of all companies:
SELECT SUM(valuation) FROM startups;

-- Find the highest amount raised by a startup:
SELECT name, MAX(raised) FROM startups;

KamiBG

 SELECT * FROM transaction_data
 LIMIT 10;

 -- full_names and emails of the transactions listing 20252 as the zip code:
 SELECT full_name, email FROM transaction_data
 WHERE zip = 20252;

 -- Find names and emails associated with ‘Art Vandelay’ for full name or a ‘der’ for their middle name:
 SELECT full_name, email FROM transaction_data
 WHERE full_name = 'Art Vandelay' OR full_name LIKE '% der %';

KamiBG

-- What years are covered by the dataset?
SELECT DISTINCT year FROM population_years;

-- What is the largest population size for Gabon in this dataset?
SELECT * FROM population_years
WHERE country = 'Gabon';

-- What were the 10 lowest population countries in 2005?
SELECT * FROM population_years
WHERE year = 2005