Op 11-feb-2011, om 10:41 heeft Nißl Reinhard het volgende geschreven:
> Hi Jay,
>
> I understand that it is not possible to define what the correct
> output is.
>
> But what I am asking for is a simple convention which doesn't
> behave more badly in general (i. e. it's still database behavior)
> but much better in my case and most likely for many cases of other
> users too.
>
> The convention is to use the dequoted column identifier as column
> name in case the column expression translates to a single identifier.
>
> You have to dequote the identifier anyway to find the column in the
> subselect to which this expression refers to.
>
> So all I'm asking for is to change the default database behavior to
> yield more obvious or consistent default column names. In case the
> database behavior doesn't fit, one has to use the AS clause anyway.
>
> For the below mentioned join, sqlite3 currently behaves like that:
>
> select [x].[a], [y].[a] from x join x y on x.a = y.a;
>
> a|a
> 1|1
>
> Hence, it simply uses the column names. And the next statement does
> that too:
>
> select [x].[a] from x;
>
> a
> 1
>
> So in my opinion the default behavior of the database should be to
> yield the same column name even for this statement:
>
> select [x].[a] from (select a from x) x;
>
> But it currently returns:
>
> [x].[a]
> 1
>
> I'd like to create a patch which changes the behavior in that way,
> but I'm not that used to the sqlite3 internals. From a quick glance
> at the source, I think it has something to do with TK_COLUMN and
> TK_VARIABLE. It would be nice if you could give me a pointer where
> to place the change in the source code.
>
> Bye.
> --
> Reinhard Nißl
Hi,
The engine already determines unquoted column names when creating
views. This also applies with inline-vies. For instance:
sqlite>.mode line
sqlite> select * from (select [x].[a] from (select a from x) x);
a = 123
This also cuts off the unnecessary table alias.
If column descriptions could be changed to be like this by default?
Edzard Pasma
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