<div dir="ltr">Add something like <br><br>where o.ctid < t1.ctid <br><br>to the inner query.<br>Also, the query doesn't need to be lateral join,<br><br>select <br><a href="http://a.name">a.name</a>,<br><a href="http://b.name">b.name</a><br>from t1 a, t1 b<br>where ST_Intersects(a.geom, b.geom) <br>and a.ctid < b.ctid;<br><br>should work the same.</div><br><div class="gmail_quote"><div dir="ltr">вс, 28 мая 2017 г. в 15:18, Olivier Leprêtre <<a href="mailto:o.lepretre@gmail.com">o.lepretre@gmail.com</a>>:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="FR" link="blue" vlink="purple"><div class="m_7124570515368415938WordSection1"><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif"">Hi,<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">Doing a lateral auto join return cross results like A,B and B,A. Is there a simple trick to avoid that ?<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">To explain : in such query<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">select <a href="http://o.name" target="_blank">o.name</a>,nam1 from <u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">t1 o,<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">lateral (select <a href="http://o.name" target="_blank">o.name</a>,t1.nam nam1 from t1<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">where st_overlaps(o.geom,t1.geom)) lat<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">order by <a href="http://o.name" target="_blank">o.name</a><u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">I get results like<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">polygon1       polygon2<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">polygon2       polygon1<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">because polygon1 overlap polygon2 and conversely.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">how could I get only one of those pairs ?<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">Thanks,<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif"">Olivier<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Verdana","sans-serif""><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p></div><div id="m_7124570515368415938DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br> <table style="border-top:1px solid #d3d4de">
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