Hello,
On 2016-04-05 19:19, Richard Hipp wrote:
> Please explain why you think it is important to know the "type" of a
> column in a view?
For the same reason as it is important in case of a table. Both could be
consistent.
> There are further inconsistencies here. Example:
>
> CREATE TABLE t1(x INTEGER);
> CREATE VIEW v1 AS SELECT x FROM t1;
> CREATE VIEW v2(x) AS SELECT x FROM t1;
> PRAGMA table_info('v1');
> PRAGMA table_info('v2');
>
> As of version 3.12.0, the two pragma's give the same answer. but in
> version 3.11.0, they were different. Which of the two answers
> returned by 3.11.0 is correct?
IMHO, INTEGER. ``v2(x)'' changes nothing but the name of the column. It
has no impact on the column's affinity.
> Or, consider this situation:
>
> CREATE TABLE t2(w SHORT INT, x DECIMAL, y BIGINT, z REAL);
> CREATE VIEW v3 AS SELECT w+x+y+z FROM t2;
>
> What should "PRAGMA table_info('v3')" report as the column type?
Opposite to the above: w+x+y+z loses affinity so it would be displayed
as an empty string.
> It seems to me that the most consistent answer is that the "type" of
> columns in a VIEW should always be an empty string.
If so, Mike's postulate is arguable. This fact could be mentioned in a
description of ``table_info'' PRAGMA: in case of views only id and a
name of a column is meaningful.
-- best regards
Cezary H. Noweta
