CREATE TABLE Students (
    StudentsID INT AUTO_INCREMENT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50),
    Email VARCHAR(50),
    GROUPP INT,
    Grade DECIMAL(5,2)
);
INSERT INTO Students (FirstName, LastName, Email, GROUPP, Grade) VALUES
('Loly', 'Tim', 'Loly.mnkljoexample.com', 103, 85 ),
('Simspon', 'Egor', 'Sim.Egor@example.com', 102, 90 ),
('Lucky', 'Alex', 'mike.johnson@example.com', 103, 96),
('Gey', 'Max', 'Gey.maxim@example.com', 103, 88 ),
('Dep', 'Williams', 'Dep.will@example.com', 102, 82 ),
('Doshik', 'Sam', 'Dos.Sam@example.com', 103, 83 ),
('Philip', 'Newya', 'Pizda@example.com', 104, 91 ),
('Toxa', 'Pedic', 'Tox.ped@example.com', 104, 84 ),
('Nefor', 'Andi', 'Nef.an@example.com', 103, 74 ),
('Dima', 'Pidorov', 'Dim.pid@example.com', 104, 99);
ALTER TABLE Students
ADD COLUMN Age INT;
ALTER TABLE Students
ADD COLUMN absences INT;
UPDATE Students
SET Age = FLOOR(RAND() * 10) + 15;
UPDATE Students SET absences = FLOOR(RAND() * 20);
SELECT AVG(absences) AS avg_absences FROM Students;
SELECT * FROM Students WHERE absences = (SELECT MAX(absences) FROM Students);
SELECT * FROM Students WHERE absences < (0.5 * (SELECT MAX(absences) FROM Students));
SELECT FirstName, LEFT(FirstName,1) AS Final_initial FROM Students;
SELECT FirstName, absences,
    CASE
        WHEN absences > 30 THEN 'Прогульщик'
        ELSE 'Не прогульщик'
    END AS absences_tag
FROM Students;