> -Original Message-
> From: pgsql-sql-ow...@postgresql.org [mailto:pgsql-sql-
> ow...@postgresql.org] On Behalf Of Wolfgang Keller
> Sent: Tuesday, April 30, 2013 2:19 PM
> To: pgsql-sql@postgresql.org
> Subject: Re: [SQL] Correct implementation of 1:n relationship with n>0?
>
> > It hi
> (there is nothing wrong in getting your hands dirty with pl/pgsql btw)
The point is that I would have expected that problem to be solved
within the past four decades since relational databases have been
invented. Or at least in the past two decades since PostgreSQL has been
developed.
>;->
Aft
> It hit me today that a 1:n relationship can't be implemented just by a
> single foreign key constraint if n>0. I must have been sleeping very
> deeply not to notice this.
>
> E.g. if there is a table "list" and another table "list_item" and the
> relationship can be described as "every list has
On 04/30/2013 04:39 PM, Wolfgang Keller wrote:
> It hit me today that a 1:n relationship can't be implemented just by a
> single foreign key constraint if n>0. I must have been sleeping very
> deeply not to notice this.
>
> E.g. if there is a table "list" and another table "list_item" and the
> rel
2013/4/30 Anton Gavazuk
> Hi,
>
> Can you explain what you are trying to achieve because it's not clear...
>
> There are 2 types of relationships which might be used in your case:
>
> 1) unidirectional relationship from list_item to list through foreign
> key on list
> 2) bidirectional relationsh
Hi,
Can you explain what you are trying to achieve because it's not clear...
There are 2 types of relationships which might be used in your case:
1) unidirectional relationship from list_item to list through foreign
key on list
2) bidirectional relationship implemented through join table which
c
2013/4/30 Wolfgang Keller
> It hit me today that a 1:n relationship can't be implemented just by a
> single foreign key constraint if n>0. I must have been sleeping very
> deeply not to notice this.
>
> E.g. if there is a table "list" and another table "list_item" and the
> relationship can be de
On Ôñé 30 Áðñ 2013 16:39:05 Wolfgang Keller wrote:
> It hit me today that a 1:n relationship can't be implemented just by a
> single foreign key constraint if n>0. I must have been sleeping very
> deeply not to notice this.
>
> E.g. if there is a table "list" and another table "list_item" and the
It hit me today that a 1:n relationship can't be implemented just by a
single foreign key constraint if n>0. I must have been sleeping very
deeply not to notice this.
E.g. if there is a table "list" and another table "list_item" and the
relationship can be described as "every list has at least one
