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If I understand this question properly, I think I am trying to do a
similar thing (get mph from two fields, Time & Distance)<br>
<br>
Not strictly local, but I wondered if the data was in SQLite,
whether one could perform the calculations there in a query through
Kexi or similar? This would update the table which is also accessed
by QGIS. The expressions would be saved, thus removing the error
possibility.<br>
<br>
<br>
<div class="moz-signature"><font font-family="Helvetica" size="3"
color="#4d583d"> Jonathan Webb <br>
Freelance GIS Specialist <br>
07941 921905 <br>
<a class="moz-txt-link-freetext" href="http://www.jwebbgis.co.uk">http://www.jwebbgis.co.uk</a><br>
<a class="moz-txt-link-freetext" href="http://uk.linkedin.com/in/jwebbgis">http://uk.linkedin.com/in/jwebbgis</a></font></div>
<div class="moz-cite-prefix">On 17/05/16 20:00,
<a class="moz-txt-link-abbreviated" href="mailto:qgis-user-request@lists.osgeo.org">qgis-user-request@lists.osgeo.org</a> wrote:<br>
</div>
<blockquote
cite="mid:mailman.59.1463511602.14625.qgis-user@lists.osgeo.org"
type="cite">Re: [Qgis-user] Local variables in field calculator</blockquote>
<br>
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