Re: updating on views

On Wed, 27 Nov 2002, XiaojingLi wrote:

> I'd like to bother you with something about updating views. At
> present, postgresql7.3doesn't support update on views.When I look up

It does if you provide the rules for what it means to do the update (and
there are some wierd issues with delete, but it is possible to get around
them)

> In my eyes, it is not very difficult to realize view update with
> fill the above three functionsBut I know the developers of
> postgresql are very learned, now that they didn't realize view update,
> maybe it is very difficult. I am a beginner of postgresql, so with my
> limited knowlege, maybe I can't realize the difficulity of doing such
> a thing. So I wonder if some of you would like to give me some advice
> about updating on views or why it is not realizedwhat's the
> difficulty of doing it?

Well, it depends. SQL updatable views are fairly limited from what I
remember and the general write your own update rules is much broader, so I
doubt anyone got terribly excited by doing the limited version. It would
take some work to define what sort of view queries are acceptable for what
sort of updates and then make the appropriate rules (imagine queries with
set value functions or UNION) without knowledge outside of the view query.