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Date: Mon, 4 Apr 2022 16:16:02 -0600
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Subject: Re: How to just get the last in a recursive query
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From: Rob Sargent <robjsargent@gmail.com>
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On 4/4/22 16:14, Shaozhong SHI wrote:
>
>
> ---------- Forwarded message ---------
> From: *Shaozhong SHI* <shishaozhong@gmail.com>
> Date: Mon, 4 Apr 2022 at 23:13
> Subject: How to just get the last in a recursive query
> To: PostGIS Users Discussion <postgis-users@lists.osgeo.org>
>
>
> In this example, Network Walking in PostGIS · Paul Ramsey 
> (cleverelephant.ca) 
> <http://blog.cleverelephant.ca/2010/07/network-walking-in-postgis.html>
>
> 3 rows got returns as follows:
>
> |id --- 6 3 1|
> ||
> |How to just get the last (namely, 1) in the most efficient way?|
> Regards, David
reverse the order of the last query and set limit 1
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    <div class="moz-cite-prefix">On 4/4/22 16:14, Shaozhong SHI wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CA+i5Jwbh6Yy-zW3AX3WLCUJANky9w8HtVo99NPxMAc9APY0zhw@mail.gmail.com">
      <meta http-equiv="content-type" content="text/html; charset=UTF-8">
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        <br>
        <div class="gmail_quote">
          <div dir="ltr" class="gmail_attr">---------- Forwarded message
            ---------<br>
            From: <strong class="gmail_sendername" dir="auto">Shaozhong
              SHI</strong> <span dir="auto">&lt;<a
                href="mailto:shishaozhong@gmail.com"
                moz-do-not-send="true" class="moz-txt-link-freetext">shishaozhong@gmail.com</a>&gt;</span><br>
            Date: Mon, 4 Apr 2022 at 23:13<br>
            Subject: How to just get the last in a recursive query<br>
            To: PostGIS Users Discussion &lt;<a
              href="mailto:postgis-users@lists.osgeo.org"
              moz-do-not-send="true" class="moz-txt-link-freetext">postgis-users@lists.osgeo.org</a>&gt;<br>
          </div>
          <br>
          <br>
          <div dir="ltr">
            <div dir="ltr">
              <div dir="ltr">In this example, <a
href="http://blog.cleverelephant.ca/2010/07/network-walking-in-postgis.html"
                  target="_blank" moz-do-not-send="true">Network Walking
                  in PostGIS · Paul Ramsey (cleverelephant.ca)</a></div>
              <div dir="ltr"><br>
              </div>
              <div>3 rows got returns as follows:</div>
              <div><br>
              </div>
              <div>
                <pre style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;margin-top:0px;margin-bottom:0px;padding:1rem;font-size:0.8rem;line-height:1.4;white-space:pre-wrap;word-break:break-all;background-color:rgb(249,249,249);border-radius:4px;color:rgb(81,81,81)"><code style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;padding:0px;font-size:16px;color:inherit;background-color:transparent;border-radius:3px"> id
---
  6
  3
  1</code></pre>
                <pre style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;margin-top:0px;margin-bottom:0px;padding:1rem;font-size:0.8rem;line-height:1.4;white-space:pre-wrap;word-break:break-all;background-color:rgb(249,249,249);border-radius:4px;color:rgb(81,81,81)"><code style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;padding:0px;font-size:16px;color:inherit;background-color:transparent;border-radius:3px">
</code></pre>
                <pre style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;margin-top:0px;margin-bottom:0px;padding:1rem;font-size:0.8rem;line-height:1.4;white-space:pre-wrap;word-break:break-all;background-color:rgb(249,249,249);border-radius:4px;color:rgb(81,81,81)"><code style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;padding:0px;font-size:16px;color:inherit;background-color:transparent;border-radius:3px">How to just get the last (namely, 1) in the most efficient way?</code></pre>
                <pre style="box-sizing:border-box;font-family:Menlo,Monaco,&quot;Courier New&quot;,monospace;margin-top:0px;margin-bottom:0px;padding:1rem;font-size:0.8rem;line-height:1.4;white-space:pre-wrap;word-break:break-all;background-color:rgb(249,249,249);border-radius:4px;color:rgb(81,81,81)">Regards, David</pre>
              </div>
            </div>
          </div>
        </div>
      </div>
    </blockquote>
    <font face="Courier New, Courier, monospace">reverse the order of
      the last query and set limit 1</font><br>
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