CREATE TABLE IF NOT EXISTS records_trainings (
    id BIGSERIAL PRIMARY KEY NOT NULL,
    user_id BIGINT NOT NULL,
    training_id BIGINT NOT NULL,
    author_id BIGINT NOT NULL,
    created_at BIGINT NOT NULL,

    CONSTRAINT fk_user FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE,
    CONSTRAINT fk_author FOREIGN KEY(author_id) REFERENCES users(id) ON DELETE SET NULL,
    CONSTRAINT fk_training FOREIGN KEY (training_id) REFERENCES trainings(id) ON DELETE CASCADE
);