create table action_comment_document (acd_id bigint generated by default  as identity primary key
    , document_id bigint references document(d_id) on delete cascade on update cascade,
                                      action_gestion_comment_id bigint references action_gestion_comment(agc_id) on delete cascade on update cascade);

alter table action_comment_document
    add constraint action_comment_document_un
        unique (document_id, action_gestion_comment_id);