Обсуждение: Information regarding foriegn key constraint.

Dear Sir,
I am a Graduate student at the University of Toledo.My Master's project
involves creating a database  in PostgreSQL version 6.5.3.I was wondering
if I can use SERIAL key along with a PRIMARY key as follows:

create table ohiouniv (uid serial primary key,
                        uname varchar(45) not null,
                        ucity varchar(25) not null);

create table departments (deptid serial primary key,
                           deptshrtn varchar(10) not null,
                           deptfulln varchar(45) not null,
                           deptphone int8 unique not null check(deptphone>0));

When I tried giving the following for linking the above 2 tables:

create table univdept (uid integer references ohiouniv,
                                     deptid integer references departments);

The error was:
create table/foreign key clause ignored; not yet implemented

Does this mean we cannot use the foreign key constraint in this version of
PostgreSQL, and if so, what is the alternative for the above problem.Please
let me know about this at your earliest convinience.
Thanks much!
Best Regards
Meeta Bhate
University of Toledo.
EECS Department.
Ph:419 450 3685.

meeta bhate writes:

> I am a Graduate student at the University of Toledo.My Master's project
> involves creating a database  in PostgreSQL version 6.5.3.I was wondering
> if I can use SERIAL key along with a PRIMARY key as follows:

(This is not the right mailing list for "wondering".)

> create table univdept (uid integer references ohiouniv,
>                                      deptid integer references departments);
>
> The error was:
> create table/foreign key clause ignored; not yet implemented

"Not implemented" really means that, but if you upgrade to the latest
version you will get foreign keys.

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter

On Fri, 8 Jun 2001, meeta bhate wrote:

> Dear Sir,
> I am a Graduate student at the University of Toledo.My Master's project
> involves creating a database  in PostgreSQL version 6.5.3.I was wondering
> if I can use SERIAL key along with a PRIMARY key as follows:
>
> create table ohiouniv (uid serial primary key,
>                         uname varchar(45) not null,
>                         ucity varchar(25) not null);
>
> create table departments (deptid serial primary key,
>                            deptshrtn varchar(10) not null,
>                            deptfulln varchar(45) not null,
>                            deptphone int8 unique not null check(deptphone>0));
>
> When I tried giving the following for linking the above 2 tables:
>
> create table univdept (uid integer references ohiouniv,
>                                      deptid integer references departments);
>
> The error was:
> create table/foreign key clause ignored; not yet implemented
>
> Does this mean we cannot use the foreign key constraint in this version of
> PostgreSQL, and if so, what is the alternative for the above problem.Please
> let me know about this at your earliest convinience.

FK constraints were added in 7.0, various fixes in 7.1 (with more
forthcoming).  Your best bet would be to upgrade if possible.  There was a
contrib module in 6.5 that did something basically fk (it didn't use the
references syntax and was installed manually as triggers).

Dear Sir,
Thanks a lot for your help.
Regards

-------------------------------------------------
MEETA BHATE
GRADUATE STUDENT,UNIVERSITY OF TOLEDO
2716 KENDALE #102
TOLEDO OH 43606
TEL:(419)-474-4208