DROP SCHEMA students;
CREATE SCHEMA students;
SET SCHEMA students;

DROP TABLE Person;
CREATE COLUMN TABLE Person(id int, name varchar(25), weight float);
DELETE FROM Person;

INSERT INTO Person VALUES(1, 'Stefan', 82.3);
INSERT INTO Person VALUES(2, 'Matthias', NULL);
INSERT INTO Person VALUES(3, 'Marcus', 70.5);
INSERT INTO Person VALUES(2, 'Matthias', NULL);

SELECT * FROM Person;
seLect naMe FRoM perSoN;

SELECT * FROM Person WHERE weight = 70.5;
SELECT SUBSTR(name, 1, 2) FROM Person;
SELECT * FROM Person WHERE name LIKE 'Ma%';

SELECT COUNT(*) FROM Person WHERE weight = 0.3;
SELECT COUNT(*) FROM Person WHERE weight = 0.3 OR weight != 0.3;

SELECT COUNT(*) FROM Person WHERE weight IS NULL;

SELECT id, CAST(weight AS INT) FROM Person;
SELECT * FROM Person WHERE CAST(weight AS INT) != 70.5;

SELECT DISTINCT * FROM Person;
SELECT id, name, weight FROM Person GROUP BY id, name, weight;