Re: Sometimes referential integrity seems not to work

scott.marlowe wrote:

> On Mon, 2 Feb 2004, Jan Wieck wrote:
> 
>> Stephan Szabo wrote:
>> 
>> > On Sat, 31 Jan 2004, Tom Lane wrote:
>> > 
>> >> Stephan Szabo <sszabo@megazone.bigpanda.com> writes:
>> >> > On Mon, 26 Jan 2004, Enio Schutt Junior wrote:
>> >> >> In a database I am working, I sometimes have to delete all the records in
>> >> >> some tables. According to the referential integrity defined in the creation
>> >> >> of the tables, postmaster should not delete the records, but it does. I have
>> >> >> used the following commands: "delete from table_1" and "truncate table_1".
>> >> >> ...
>> >> >> can the postgres user delete records despite referential integrity?
>> >>
>> >> I think the first PG release or two that had TRUNCATE TABLE would allow
>> >> you to apply it despite the existence of foreign-key constraints on the
>> >> table.  Recent releases won't though.
>> > 
>> > Yeah, truncate didn't worry me much, but the implication that delete from
>> > table_1; worked did.
>> 
>> TRUNCATE cannot be used inside of a transaction, and since 7.3 it checks 
>> for foreign keys. So I guess Enio is getting but ignoring the error 
>> message when trying the delete, but then the truncate does the job in 
>> his pre-7.3 database.
> 
> Yes it can.  I think it was starting in 7.3.

Okay, so you're the third one correcting me on this. Now can any of you 
violate a foreign key constraint with anything else than using truncate 
in a pre-7.3 database? Because I can't do that and that was the original 
problem.


Jan

> 
> => select * from test2;
>     info
> -------------
>  abc'123
> 123
> (2 rows)
> 
> => begin;
> BEGIN
> => truncate test2;
> TRUNCATE TABLE
> => rollback;
> ROLLBACK
> => select * from test2;
>     info
> -------------
>  abc'123
> 123
> 
> 
> 
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