6.University Database - SoftUni

create table majors
(
    major_id int auto_increment primary key,
    name     varchar(50)
);

create table payments
(
    payment_id     int,
    payment_date   date,
    payment_amount decimal(8, 2),
    student_id     int,
    primary key (student_id, payment_id)
);

create table students
(
    student_id     int primary key auto_increment,
    student_number varchar(12),
    student_name   varchar(50),
    major_id       int,
    constraint fk_students_payments
        foreign key students (student_id)
            references payments (student_id),
    constraint fk_students_majors
        foreign key (major_id)
            references majors (major_id)
);

create table subjects
(
    subject_id   int primary key auto_increment,
    subject_name varchar(50)
);

create table agenda
(
    student_id int,
    subject_id int,
    primary key (student_id, subject_id),
    constraint fk_agenda_subjects
        foreign key agenda (subject_id)
            references subjects (subject_id),
    constraint fk_agenda_students
        foreign key (student_id)
            references students (student_id)
);