1_solution.sql

--1. Find the country that start with Y

SELECT name FROM world
  WHERE name LIKE 'Y%';

--2. Find the countries that end with y

SELECT name FROM world
  WHERE name LIKE '%y';

--3. Find the countries that contain the letter x

SELECT name FROM world
  WHERE name LIKE '%x%';

--4. Find the countries that end with land

SELECT name FROM world
  WHERE name LIKE '%land';

--5. Find the countries that start with C and end with ia

SELECT name FROM world
  WHERE name LIKE 'C%ia';

--6. Find the country that has oo in the name

SELECT name FROM world
  WHERE name LIKE '%oo%';

--7. Find the countries that have three or more a in the name

SELECT name FROM world
  WHERE name LIKE '%a%a%a%';

--8. Find the countries that have "t" as the second character.

SELECT name FROM world
 WHERE name LIKE '_t%'
ORDER BY name;

--9. Find the countries that have two "o" characters separated by two others.

SELECT name FROM world
 WHERE name LIKE '%o__o%';

--10. Find the countries that have exactly four characters.

SELECT name FROM world
 WHERE name LIKE '____';

--11. Find the country where the name is the capital city.

SELECT name
  FROM world
 WHERE name = capital;

--12. Find the country where the capital is the country plus "City".

SELECT name
  FROM world
 WHERE capital = concat(name, ' City');

--13. Find the capital and the name where the capital includes the name of the country.

SELECT capital,name FROM world WHERE capital LIKE concat('%', name, '%');

--14. Find the capital and the name where the capital is an extension of name of the country.

SELECT name, capital FROM world WHERE capital LIKE concat('%', name, '%') AND capital > name;

--15. Show the name and the extension where the capital is an extension of name of the country.

SELECT name, REPLACE(capital, name, '') FROM world WHERE capital LIKE concat('%', name, '%') AND capital > name;