[Haskell-cafe] Using HaskellDB on Tables that contain same column
names
Justin Bailey
jgbailey at gmail.com
Mon Nov 2 11:10:02 EST 2009
I'd recommend sending HaskellDB questions to the haskelldb users
mailing list. You do need to subscribe first. Now to your question:
On Sat, Oct 31, 2009 at 2:38 AM, R. Emre Başar <reb at cs.bilgi.edu.tr> wrote:
> Hi all,
> project (Server.name << s!Server.name #
> Vendor.name << v!Vendor.name #
> Model.name << m!Model.name #
> Server.system_id << s!Server.system_id)
>
This is by design. Just like in SQL, the column names are not
disambiguated. If you wrote a SQL query like:
select * from Server join Model on ... join Vendor on ...
you would get duplicate column names. You must use unique column names
in the projection. Check out the haskelldb-th package for Template
Haskell utils for easily creating column names if you don't want to
declare them by hand.
Justin
More information about the Haskell-Cafe
mailing list