Re: How get column-wise table info from an arbitrary query? - Mailing list pgsql-general

From Kenneth Tilton
Subject Re: How get column-wise table info from an arbitrary query?
Date
Msg-id CAECCA8YgfRzuu37EA-XzHmhyu+CGL1aNDjLCBq8RePR8UTkGgg@mail.gmail.com
Whole thread Raw
In response to Re: How get column-wise table info from an arbitrary query?  (Raymond O'Donnell <rod@iol.ie>)
List pgsql-general


On Tue, Dec 4, 2012 at 8:26 PM, Raymond O'Donnell <rod@iol.ie> wrote:
On 05/12/2012 01:11, Raymond O'Donnell wrote:
> On 05/12/2012 01:04, Kenneth Tilton wrote:
>> I am porting from MySQL some code that has to take an arbitrary query
>> involving joins and build up a dictionary (in an HLL talking to Postgres
>> over a socket) where each column name will be the key. The catch is that
>> there will be duplicate entries where two joined tables have the same
>> column such as "id", so I have to get the source table for each column.
>> Here is a sample query:
>>
>>    select * from providers p inner join provider_types pt on pt.id
>> <http://pt.id> = p.provider_type_id;
>>
>> I actually figured out how to get the table OID which would suffice, but
>> I am porting MySQL code that could get fully qualified column names
>> including a table alias if that were used. We allow other code to look
>> up values in the dictionary with the alias as a prefix as a convenience,
>> eg. "p.id <http://p.id>" or "pt.id <http://pt.id>".
>
> Maybe I'm misunderstanding, but why don't you just give the columns an
> alias directly? -
>
>    select p.id as p_id, pt.id as pt_id, ....

Sorry, I *am* misunderstanding - I missed the "arbitrary" bit. Too late
at night to be working...

<g> No harm, and I did consider that as a brute force workaround, because we are already a little brittle in that we are assuming "p" as the table alias. So we /could/ do:

   select p.id p_id, p.*, pt.id pt_id, pt.* ...etc...

Hmmm, that might be the easy way out, albeit brute. :)

Thx, kt


Ray.


--
Raymond O'Donnell :: Galway :: Ireland
rod@iol.ie



--
Kenneth Tilton

Director of Software Development

MCNA Dental Plans
200 West Cypress Creek Road
Suite 500
Fort Lauderdale, FL 33309
ktilton@mcna.net (Email)

www.mcna.net (Website)CONFIDENTIALITY NOTICE: This electronic mail may contain information that is privileged, confidential, and/or otherwise protected from disclosure to anyone other than its intended recipient(s). Any dissemination or use of this electronic mail or its contents by persons other than the intended recipient(s) is strictly prohibited. If you have received this communication in error, please notify the sender immediately by reply e-mail so that we may correct our internal records. Please then delete the original message. Thank you.


pgsql-general by date:

Previous
From: Raymond O'Donnell
Date:
Subject: Re: How get column-wise table info from an arbitrary query?
Next
From: "Gauthier, Dave"
Date:
Subject: how do I grant select to one user for all tables in a DB?