table has a many to many relationship with itself ... ?

Поиск
Список
Период
Сортировка
От Daniel McBrearty
Тема table has a many to many relationship with itself ... ?
Дата
Msg-id 9cf113670606130801o7772265fn1b7971304426e42b@mail.gmail.com
обсуждение исходный текст
Ответы Re: table has a many to many relationship with itself ... ?
Список pgsql-general
Hi

I have a table "phrases" that looks like this :

create table phrases(
  id serial ,
  language integer references langauges(id),
  content text
);


Simply a word or phrase in some language.

Now I want to express the concept of a "translation". A translation is
a number of phrases from different languages that are a translation of
each other. There is nothing else to say about a translation - though
it does need to be referencable by other tables, so it needs an ID.

One way to do this is with these two tables:

create table translations (
  id serial primary key
);

create table translations_to_phrases (
  translation_id integer references translations(id),
  phrase_id integer references phrases(id),
  primary key (translation_id, phrase_id)
);

Now this actually works as a data structure; the translations table is
a bit odd, having only an id, but that is all we really need.

Can I do this though? can I create a row in translations?

insert into table translations ... insert what?

The other way to do this that I see is to lose the link table
translations_to_phrases, and then make translations

create table translations (
  id serial primary key,
  phrases integer[]
);


but it seems that I can no longer make postgre aware that the integers
in translations(phrases) are references.

What is the best solution?

Thanks

Daniel

--
Daniel McBrearty
email : danielmcbrearty at gmail.com
www.engoi.com : the multi - language vocab trainer
BTW : 0873928131

В списке pgsql-general по дате отправления:

Предыдущее
От: Jim Nasby
Дата:
Сообщение: Re: VACUUMing sometimes increasing database size / sometimes
Следующее
От: gl@lbn.fr
Дата:
Сообщение: Re: pg_dump: missing pg_database entry