CURSO

1. La segunda Colegiatura más alta.

SUB-QUERY en el WHERE

SELECT DISTINCT colegiatura
FROM platzi.alumnos AS a1
WHERE 2 = (
	SELECT COUNT (DISTINCT colegiatura)
	FROM platzi.alumnos a2
	WHERE a1.colegiatura <= a2.colegiatura;

LIMIT y OFFSET

SELECT DISTINCT colegiatura
FROM platzi.alumnos
ORDER BY colegiatura DESC
LIMIT 1 OFFSET 1;

WHERE y LIMIT, OFFSET

SELECT DISTINCT colegiatura,
  tutor_id
FROM platzi.alumnos
WHERE tutor_id = 20
ORDER BY colegiatura DESC
LIMIT 1 OFFSET 1;

1. Todos los registros y la Data que tienen la segunda colegiatura más alta.

SUB-QUERY en el INNER JOIN

SELECT *
FROM platzi.alumnos AS datos_alumnos
INNER JOIN (
			SELECT DISTINCT colegiatura
			FROM platzi.alumnos
			WHERE tutor_id = 20
			ORDER BY colegiatura DESC
			LIMIT 1 OFFSET 1
		) AS segunda_mayor_colegiatura
	ON datos_alumnos.colegiatura = segunda_mayor_colegiatura.colegiatura;

SUB-QUERY en el WHERE

SELECT *
FROM platzi.alumnos AS datos_alumnos
WHERE colegiatura = (
		SELECT DISTINCT colegiatura
		FROM platzi.alumnos
		WHERE tutor_id = 20
		ORDER BY colegiatura DESC
		LIMIT 1 OFFSET 1
	);

RETO:

Mostrar la segunda mitad de la tabla platzi.alumnos.

WHERE

SELECT *
FROM platzi.alumnos
WHERE id > 500;

LIMIT

SELECT *
FROM platzi.alumnos
LIMIT 500 OFFSET 500;

LIMIT, OFFSET

SELECT *
FROM platzi.alumnos
OFFSET 499;

WINDOW, OFFSET, SUB-QUERY

SELECT ROW_NUMBER() OVER () AS row_id, *
FROM platzi.alumnos
OFFSET (
	SELECT COUNT (*)/2
	FROM platzi.alumnos
);

OFFSET, SUB-QUERY

SELECT *
FROM platzi.alumnos
OFFSET (
	SELECT COUNT (*)/2
	FROM platzi.alumnos
);