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Thread: Re: ALTER TABLE doc small thing

Re: ALTER TABLE doc small thing

From
Grzegorz Szpetkowski
Date:
"NOTE 30 — If MATCH FULL or MATCH PARTIAL is specified for a
referential constraint and if the referencing table has only one
column specified in <referential constraint definition> for that
referential constraint, or if the referencing table has more than one
specified column for that <referential constraint definition>, but
none of those columns is nullable, then the effect is the same as if
no
<match type> were specified."

I found that in SQL:2003 draft, so in above case MATCH FULL is
syntactically ok, but rather confusing and effectively do nothing
(maybe just impression purpose).

Regards,
G. Sz.

2011/5/9 Grzegorz Szpetkowski <gszpetkowski@gmail.com>:
> http://www.postgresql.org/docs/9.0/static/sql-altertable.html
>
> "To add a foreign key constraint to a table:
>
> ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address)
> REFERENCES addresses (address) MATCH FULL;"
>
> This looks confusing to me. Is "MATCH FULL" works with non-composite
> (one adress column) foreign keys at all ?
>
> Regards,
> G. Sz.
>

Re: ALTER TABLE doc small thing

From
Robert Haas
Date:
On Mon, May 9, 2011 at 2:12 PM, Grzegorz Szpetkowski
<gszpetkowski@gmail.com> wrote:
> "NOTE 30 — If MATCH FULL or MATCH PARTIAL is specified for a
> referential constraint and if the referencing table has only one
> column specified in <referential constraint definition> for that
> referential constraint, or if the referencing table has more than one
> specified column for that <referential constraint definition>, but
> none of those columns is nullable, then the effect is the same as if
> no
> <match type> were specified."
>
> I found that in SQL:2003 draft, so in above case MATCH FULL is
> syntactically ok, but rather confusing and effectively do nothing
> (maybe just impression purpose).

I guess we could remove it, but I don't think it's really doing any harm.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Re: ALTER TABLE doc small thing

From
Bruce Momjian
Date:
Robert Haas wrote:
> On Mon, May 9, 2011 at 2:12 PM, Grzegorz Szpetkowski
> <gszpetkowski@gmail.com> wrote:
> > "NOTE 30 ? If MATCH FULL or MATCH PARTIAL is specified for a
> > referential constraint and if the referencing table has only one
> > column specified in <referential constraint definition> for that
> > referential constraint, or if the referencing table has more than one
> > specified column for that <referential constraint definition>, but
> > none of those columns is nullable, then the effect is the same as if
> > no
> > <match type> were specified."
> >
> > I found that in SQL:2003 draft, so in above case MATCH FULL is
> > syntactically ok, but rather confusing and effectively do nothing
> > (maybe just impression purpose).
>
> I guess we could remove it, but I don't think it's really doing any harm.

I find the MATCH FULL makes the example less real-world accurate, so I
removed the specification from the example.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +