Re: Query about foreign key details for php framework

On 02/28/2016 03:42 PM, David Binney wrote:
> Hey adrian,
>
> rc.constraint_name AS name,
> tc.constraint_type AS type,
> kcu.column_name,
> rc.match_option AS match_type,
> rc.update_rule AS on_update,
> rc.delete_rule AS on_delete,
> kcu.table_name AS references_table,
> kcu.column_name AS references_field,
> kcu.ordinal_position
>
> Those are the columns that i need as a minimum, but as you know they are
> all easy apart from the rules "on update" from the "RC" table.

I am not following, update_rule is just a field in
information_schema.referential_constraints, how is it any harder then
delete_rule?

The issue from what I understand is that
information_schema.referential_constraints does not have a table_name
field to constrain the information to a particular table. This leads
back to the overriding question, what is the purpose of the query? I
suspect it for use by the framework to set up attributes of a model
based on a table, is that correct?

>
> I did start having a crack at the catalog tables but that is pretty
> complicated.
>
> On Sun, 28 Feb 2016 at 01:21 Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 02/26/2016 08:29 PM, David Binney wrote:
> > Hey adrian,
> >
> > You are correct that the distinct will chomp the resultset down
> to the
> > correct count, I am just concerned that there will be cases where it
> > might not be accurate between the "rc" and the "kcu" joins as
> there is
> > no table reference. I have simplified the query right down to
> just the
> > join that i am unsure about. You can see below that as soon as i
> add the
> > rc.unique_constraint_name, the distinct is no longer returning
> one row.
> > In this case its fine because the rc values are the same and would
> > distinct away, but there might be a case where they are diferent
> and you
> > would have two rows and not know which values are correct?
> >
>
> Well it comes down to the question that was asked several times
> upstream:
>
> what is the information you want to see?
>
> I am not talking about a query, but a description of what attributes you
> want on what database objects.
>
> Also given, from previous post:
>
> "I am a little in the dark as well since this is just a broken piece of
> ORM i am attempting to fix, in the framework."
>
> Is this not something that should be discussed with the framework
> developers, or are we already doing that:)?
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>
> --
> Cheers David Binney

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com