[Qgis-user] Ratio vector classification question (QGIS Desktop 2.12.1 with GRASS 6.4.3)

[DelazJ]

Hi,
John, this means there's already a field named "AREA" in the data you
downolad (and this needs to be fixed - see
https://github.com/qgis/QGIS-Documentation/issues/457).
To bypass this issue, do the exercise with a new field named AREA2.

Regards,
DelazJ

2016-02-14 23:54 GMT+01:00 John Charde <johnchardeiv at gmail.com>:

> Hi all,
>
> I am following the QGIS training guide (complete with datasets it had me
> download) and am working with vector classifications. After the guide
> prompted me create a nominal classification of the "landuse" layer, it went
> into ratio classification. I added an AREA column to the attribute table,
> and used the attribute calculator to find the areas of all attributes (with
> the "type" box set as "decimal number"). I changed the classification style
> to "Graduated," changed the "column" to AREA, created my own color ramp and
> classified the data. after I clicked "OK" through the prompts to get back
> to the main screen, I tried to save the style and toggle off editing, and I
> got an error stating the following:
>
> Could not commit changes to layer landuse
>
>
> Errors: ERROR: 1 new attribute(s) not added
>
> ERROR: 55 attribute value change(s) not applied.
>
> Provider errors:
>
> SQLite error: duplicate column name: AREA
>
> SQL: ALTER TABLE "landuse" ADD COLUMN "AREA" FLOAT
>
> SQLite error: near "WHERE": syntax error
>
> SQL:
>
>
>
> I'm not sure what it means and what I am supposed to do to rectify the
> situation. Could anyone help me? I greatly appreciate it!
>
>
> Best,
>
>
>       Jack C. (new QGIS user)
>
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> List info: http://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20160215/0dbd804c/attachment.html>