create table resources (
    id           integer, 
    language     text, 
    name         text, 
    surname      text,
    patronymic   text,
    primary key (id, language),
    constraint chk_language check(language in ('RU', 'EN', 'UA'))
);

create table classes(
    id         integer primary key, 
    fio_res_id integer, 
    age        integer, 
    phone      text
);

insert into classes(id, fio_res_id, age, phone) values(1, 1, 5, '88888');
insert into classes(id, fio_res_id, age, phone) values(1, 2, 36, '99999');
insert into resources(id, language, name, surname, patronymic) values(1, 'EN', 'Ivan', 'Ivanov', 'Ivanovich');
insert into resources(id, language, name, surname, patronymic) values(1, 'RU', 'Иван', 'Иванов', 'Иванович');
insert into resources(id, language, name, surname, patronymic) values(1, 'UA', 'Iван', 'Iванов', 'Iванович');
insert into resources(id, language, name, surname, patronymic) values(2, 'EN', 'Petr', 'Petrov', 'Petrovich');
insert into resources(id, language, name, surname, patronymic) values(2, 'RU', 'Петр', 'Петров', 'Петрович');
insert into resources(id, language, name, surname, patronymic) values(2, 'UA', 'Пэтро', 'Пэтров', 'Пэтрович');

select c.id, r.surname, r.name, r.patronymic, c.age, c.phone
from classes c
inner join resources r on r.id = fio_res_id and r.language = 'RU'