delimiter //
create procedure setCountries()
begin
	insert into countries (name) values
    ('Россия'), ('Украина'), ('Беларусь');
end//
delimiter ;

delimiter //
create procedure setShops()
begin
	set @i = 1;
    set @maxId = (select max(id) from countries);
	loop1: loop
		insert into shops (name, countryId)
        values (concat('shop', @i), floor(rand() * @maxId) + 1);
        set @i = @i + 1;
        if @i > 10 then leave loop1; end if;
    end loop loop1;
end//
delimiter ;

delimiter //
create procedure setAuthors()
begin
	set @i = 1;
    set @maxId = (select max(id) from countries);
	loop1: loop
		insert into authors (name, surname, countryId)
        values (
			concat('author', @i),
            concat('surname', @i),
            floor(rand() * @maxId) + 1
		);
        set @i = @i + 1;
        if @i > 100 then leave loop1; end if;
    end loop loop1;
end//
delimiter ;

delimiter //
create procedure setThemes()
begin
	insert into themes (name)
    values ('Детектив'), ('Роман'), ('Фэнтези');
end//
delimiter ;

delimiter //
create procedure setBooks()
begin
	set @i = 1;
	loop1: loop
		set @authorId = (
			select id from authors order by rand() limit 1
		);
        set @themeId = (
			select id from themes order by rand() limit 1
        );
		insert into books (
			name, pages, price, publishDate, authorId, themeId
        ) values (
			concat('book', @i), floor(rand() * 500) + 20,
            rand() * 500000 / 100 + 100,
            current_timestamp(), @authorId, @themeId
        );
        set @i = @i + 1;
        if @i > 500 then leave loop1; end if;
    end loop loop1;
end//
delimiter ;

call setBooks();

delimiter //
create procedure setSales()
begin
	set @i = 1;
	loop1: loop
		set @bookId = (select id from books order by rand() limit 1);
        set @price = (select price from books where id = @bookId);
        set @shopId = (select id from shops order by rand() limit 1);
        set @quantity = (select floor(rand() * 100) + 1);
		insert into sales (price, quantity, saleDate, bookId, shopId)
        values (@price, @quantity, current_timestamp(), @bookId, @shopId);
        set @i = @i + 1;
        if @i > 1000 then leave loop1; end if;
    end loop loop1;
end//
delimiter ;

call setCountries();
call setShops();
call setAuthors();
call setThemes();
call setBooks();
call setSales();