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<p class=MsoNormal><span lang=EN-US>Hello<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I am trying to aggregate linestrings
together based on their attributes and the fact that they are touching each
other.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Therefore I found out how to write a very
basic aggregate function :<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> CREATE AGGREGATE geometry_sum
(<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> SFUNC
= st_union,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> BASETYPE
= geometry,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> STYPE
= geometry);<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I can now aggregate my linestrings grouped
by their names, importance, and so on but … I have trouble to group them
by the fact that they are touching each other.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>e.g.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>linestring A, B and C have the same attributes
but only A and B are touching each other.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I would like as a result A+B in one record,
and C in a second record.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Does someone have any tips to share ?<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Thank you,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Nicolas<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
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