Interesting, thanks! Do you know why the first one fails instead of doing that renaming process, while
your version succeeds?
On Monday, September 5, 2016, Adrian Klaver <
adrian.klaver@aklaver.com> wrote:
On 09/05/2016 12:55 PM, Ryan Murphy wrote:
Hello, I have a question about views in Postgres.
Given a table like so:
create table todo (
id serial,
task text,
done_time timestamp default null
);
it is legal (though perhaps not advised, by some) to query it like so:
select task, * from todo;
This gives a result with 2 redundant "task" fields (with duplicate names):
task | id | task | done_time
--------------+----+--------------+-----------
wash the dog | 1 | wash the dog |
However, if I try to make a view of this I hit a problem: views can't
have duplicate field names:
create view task2 as select task, * from todo;
ERROR: column "task" specified more than once
I understand this may seem like a silly thing to want to do, but my
question is if there is an easy way to automatically de-dup the columns
of the query so I can create a view from it. Or is there any
fundamental reason why views can't be allowed to have duplicate columns,
just like the result set above?
test=> create view task2 as select task AS task_1 , * from todo;
CREATE VIEW
test=> \d task2
View "public.task2"
Column | Type | Modifiers
-----------+-----------------------------+-----------
task_1 | text |
id | integer |
task | text |
done_time | timestamp without time zone |
Thanks!
Ryan
--
Adrian Klaver
adrian.klaver@aklaver.com