Re: [?big5?]

=?big5?B?bmd0ZXJyeQ==?= wrote:
>
> I am sorry what I am trying is:
>
> >CREATE TABLE purchase (id int, po int, date date, PRIMARY KEY (id));
> >
> >CREATE TABLE lcopen (lc numeric, po int, PRIMARY KEY (lc));
>
> replace with:
> CREATE TABLE lcopen (lc numeric, po int REFERENCES purchase (po), PRIMARY KEY (lc));
> but there is an error and I do not how to correct that.

    You  should get an error saying that "po" is missing a UNIQUE
    constraint.  So go ahead and make it unique.


Jan

>
> >
> >CREATE TABLE lcreceive (
> >   id int,
> >   lc numeric REFERENCES lcopen(lc),
> >   purid int REFERENCES purchase(id)
> >)
> >;
> >
> >I think this is what you are asking this will effectively make lc and
> >purid in lcreceive foreign keys of the other tables
> >
> >Darren Ferguson
> >
> >On Sun, 10 Mar 2002, [big5] ngterry wrote:
> >
> >>
> >> Hi!
> >>
> >> I am just a newbie in postgresql.  What if:
> >>
> >> CREATE TABLE purchase (id int, po int, date date, PRIMARY KEY (id));
> >>
> >> CREATE TABLE lcopen (lc numeric, po int, PRIMARY KEY (lc));
> >>
> >> CREATE TABLE lcreceive (id int, lc numeric REFERENCES lcopen, purid int REFERENCES purchase);
> >>
> >> How do I refer the keywords po in table lcopen to table purchase the po keywords?  I am quite confuse, since I
haveannounce id in table purchase as PRIMARY KEY.  I do not know how to key another keywords. 
> >>
> >> Best regards,
> >>
> >> Terence
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# It's easier to get forgiveness for being wrong than for being right. #
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