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

From Kenneth Tilton
Subject How get column-wise table info from an arbitrary query?
Date
Msg-id CAECCA8agjz9SDaRQmKhy2U=_id4827MvC_h7tvAhLoTfeh-uag@mail.gmail.com
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Responses Re: How get column-wise table info from an arbitrary query?
Re: How get column-wise table info from an arbitrary query?
List pgsql-general
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 = 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" or "pt.id".

I can easily fake this if we predefine a unique alias<->table pairing (which we follow anyway), but if Postgres itself offers this it would be that much cleaner. So:

Is there any way on an arbitrary query to determine column names qualified by table aliases?

Thx, kt

--
Kenneth Tilton

Director of Software Development

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

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