[Qgis-user] QGIS 2.10.1 adding PostGIS Views

[Jürgen E. Fischer]

Hi Andrea,

On Fri, 04. Sep 2015 at 10:18:31 +0200, Andrea Peri wrote:
> The first is to allow a standard access to a view only readonly .

That's already the case - but it doesn't solve that various other functions
(eg. attribute table, selection) also require a unique feature id.

> select count(distinct (field1, field2)) from view;

That's already done to verify that the manual pk selection is correct and leads
to and layer insertion error, if it's not.   But that is often very expensive
and therefore is not done in the dialog.  It's even not even verified in case
"use estimated metadata" is on in the connection.
 
> I complex step could be to link the field of the view to the field of a table.

What for?

> I guess this link is not provided directly from postgres.

It is - for simple fields.  But there also are expressions (think: aggregates,
store procedures call etc.), that aren't covered.   And there information about
the base fields doesn't tell you much about the situation in the view if there
are joins - a field unique in the base table is not necessarily unique in a
join with other tables.


Jürgen

-- 
Jürgen E. Fischer           norBIT GmbH             Tel. +49-4931-918175-31
Dipl.-Inf. (FH)             Rheinstraße 13          Fax. +49-4931-918175-50
Software Engineer           D-26506 Norden             http://www.norbit.de
QGIS release manager (PSC)  Germany                    IRC: jef on FreeNode                         
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