Using the foreign key constraints to propose automatically created
relations to the user would be a nice feature for any database. One
problem here is, that the providers handle the database management
themselves and only provide QGIS the information that there is a layer,
but not from what database it comes. Maybe it would be possible to
extract this information with the current architecture but for an
optimal handling the provider architecture should be adapted to provide
such information in a standard way.
Matthias
On 05/28/2014 10:54 PM, Bob and Deb wrote:
How about querying the sqlite_master table to find the data type? And
why not use the constraints found in this query to set up the qgis
relations?
-Bob (aka cgs_bob on freenode)
On May 27, 2014 6:04 AM, "Régis Haubourg"
<[email protected]
<mailto:[email protected]>> wrote:
Hugo Mercier wrote
> Or
>> calculated fields in view can't be explicitly cast, so QGIS
should have
>> to
>> guess data type based on a data scan (a major unadressed issue
of sqlite)
>
> Hmmm I wasn't aware of this limitation in SQLITE views :(
Yes, SQLITE does dynamic typing, so user or provider has to scan
values to
guess the right type.
Here is a sqlite topic on that [0]
And here my initial post in qgis list [1]
[0]
http://sqlite.1065341.n5.nabble.com/Computed-columns-in-VIEWs-return-NULL-but-should-be-able-to-be-typed-Any-ideas-td56769.html#a56770
[1]
http://osgeo-org.1560.x6.nabble.com/Spatialite-can-t-type-fields-of-a-view-td5058436.html
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