How get column-wise table info from an arbitrary query?

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

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