[Qgis-user] ordering an attribute table

[Michael Spencer]

 Date: Thu, 26 Sep 2013 18:18:10 +0200
From: Bernhard Str?bl <bernhard.stroebl at jena.de>

Hi,

Am 26.09.2013 18:07, schrieb Michael Spencer:
> Having a strange problem at the moment.
>
> If I open a vector attribute table and click on a column heading to sort
> the column then this doesn't seem to work. The column contains mainly
> numbers with some NA and some NULL strings.
>
> The sort action groups most together most NA and NULL, and orders the
> numbers, but some strings slip through the gaps and appear where they
> aren't wanted in the number sequence!
>
> I'm working in QGIS 2.0.1 on Ubuntu 12.04.
>
> The reason I want to do this is to delete all records that aren't
> numeric, so if there's a neater way to accomplish this that would be
great!

A neater way would be to select the records in question and then simply
delete the selected. Hint select for nulls with
<code>"my_field" is null</code>

Thanks Bernhard, this was my original choice. Unfortunately I find the
select tool a total black box and can't get my head around it. Your
suggestion works for entries with 'null' in, but I can't get a response
when I want to select 'nan' values. I've tried as:

<"field" is nan>
<"field" is 'nan'>
<"field" = 'nan'>

Both with no joy. Is there a crib sheet somewhere with basic options on?

Ta,
Michael

Bernhard

>
> Ta,
> Michael
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