<HTML><BODY><div class="js-helper js-readmsg-msg"><div><div id="style_14092938490000000436_BODY">Thanks Daniel<br><br>Now I add new data in the network through QGIS (GRASS feature v.clean creates the segments from roads perfectly) and the DB trigger keeps the "road_noded" and "road_noded_vertices_pgr" tables duly.<br><br>Regards<br><br>Mon, 25 Aug 2014 11:53:08 +0200 от Daniel Kastl <daniel@georepublic.de>:<br>
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<div><div dir="ltr"><br><div><br><br><div>On Mon, Aug 25, 2014 at 11:00 AM, Vladimir <span dir="ltr"><<a href="//e.mail.ru/compose/?mailto=mailto%3afl_v@inbox.ru" target="_blank">fl_v@inbox.ru</a>></span> wrote:<br>
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<div>Hi All<br><br><p>I have a road network with appending a new segments sometimes.</p><p>Then I copy the new segments into my "road_noded" table and execute <br>------------------- <br>SELECT pgr_createTopology('roads_noded', 0.1, 'geom', 'id',rows_where:='id > a last id')<br>
------------------<br>for affecting on the new segments only. But this action recreates my "road_noded_vertices_pgr" table completely for the new segments instead of appending the new vertices and referencing them to the new segments.</p>
<p>1) Is pgr_createTopology only for create not for update? Somebody knows other method or some trick?</p></div></blockquote><div>Yes, this function does not do updates.</div><div>If you add or modify roads later, and if you don't want to keep old node ID's, then you can't use this function.</div>
<div> </div><blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><p>2) Could I use native Postgis functions (ST_StartPoint,ST_EndPoint etc) in the event if no possibility?</p>
</div></blockquote><div>I don't understand what you mean with "event", but yes, you can use any PostGIS function to handle the updates. You could for example a trigger function.</div><div><br></div><div>Daniel</div>
</div><br clear="all"><div><br></div>-- <br><div dir="ltr"><span style="font-family:arial,sans-serif;font-size:13px;border-collapse:collapse">Georepublic UG & Georepublic Japan<br>eMail: <a href="//e.mail.ru/compose/?mailto=mailto%3adaniel.kastl@georepublic.de" style="color:rgb(66,99,171)" target="_blank">daniel.kastl@georepublic.de</a><br>
Web: <a href="http://georepublic.info" style="color:rgb(66,99,171)" target="_blank">http://georepublic.info</a></span></div>
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