<div dir="ltr">Hello,<div><br></div><div>I'm not sure If I followed your question, but in my experience with QGIS editing Postgres\postgis spatial tables, I add some smal hickups, but never with splitting.</div><div><br>
</div><div>If its a normal polygon and you wish to split it with a line, QGIS will assign to all your new polygons a nextval('yourtable_gid_seq'::regclass), and this should solve the PK's problem.</div><div><br>
</div><div>If it's a multipart polygon that you want to spit it's parts, you can use the multipartsplit plugin, and it will also take care of your primary keys.</div><div><br></div><div>Maybe it's a problem with your table, please send the creation SQL command and maybe someone can have a clue of what is happening.</div>
<div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Oct 7, 2013 at 10:41 AM, Peter Brown <span dir="ltr"><<a href="mailto:peterbrown.kew@gmail.com" target="_blank">peterbrown.kew@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks for your prompt response, it is nice to know that it is possible, but the methods you remember do seem to have problems. <div>
- in QGIS I can split a polygon which is on a layer, and under the 'layer' option on the menu, I call up the attributes table, but that only offers me all the fields in the base PostGIS table EXCEPT (a) the ID and (b) the geometry</div>
<div>- I have tried manufacturing another PostGIS table with all the attributes of the polygon except an ID field with all its 'NO NULLS' etc, but then when I open a layer in QGIS it draws the polygon but shows it as not editable</div>
<div>You have obviously managed something clever, but I am not quite sure what</div><div>Regards</div><div>Peter Brown</div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div class="h5">On 7 October 2013 09:32, Hugues François <span dir="ltr"><<a href="mailto:hugues.francois@irstea.fr" target="_blank">hugues.francois@irstea.fr</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><u></u>
<div>
<div dir="ltr" align="left"><font color="#0000ff" face="Arial"><span>Hello,</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="Arial"><span></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="Arial"><span>I previously edited polygons from postgis within
qgis and with no problem. If I remember well, before saving I also filled
attribute data to give a new ID. Maybe if you just want to edit polygons without
changing attributes, you may remove constraints on your postgis table
(especially, uniques, not null and primary key) before editing (and then put the
things right back to postgis).</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="Arial"><span></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="Arial"><span>Hugues.</span></font></div>
<div> </div>
<div align="left"> </div><br>
<div dir="ltr" lang="fr" align="left">
<hr>
<font face="Tahoma"><b>From:</b> <a href="mailto:postgis-users-bounces@lists.osgeo.org" target="_blank">postgis-users-bounces@lists.osgeo.org</a>
[mailto:<a href="mailto:postgis-users-bounces@lists.osgeo.org" target="_blank">postgis-users-bounces@lists.osgeo.org</a>] <b>On Behalf Of </b>Peter
Brown<br><b>Sent:</b> Monday, October 07, 2013 9:53 AM<br><b>To:</b>
<a href="mailto:postgis-users@lists.osgeo.org" target="_blank">postgis-users@lists.osgeo.org</a><br><b>Subject:</b> [postgis-users] Saving a split
polygon<br></font><br></div><div><div>
<div></div>
<div dir="ltr">In Quantum GIS (QGIS) there is a very useful facility for taking a
polygon in a PostGIS database linked to QGIS and splitting it. HOWEVER, when one
then tries to save the two portions, PostGIS puts up an error message that it
cannot save the new portion because it does not have a new ID (it can save the
existing portion, because this is only an edit of an existing ID).
<div>There are workarounds for this (e.g. convert to 'Shape' files) but they
seem incredibly clumsy. Does anyone have a more direct solution?</div>
<div>Thanks</div>
<div>Peter Brown<br>
<div> </div></div></div></div></div></div>
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