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From: Shaozhong SHI <[email protected]>
To: Rob Sargent <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: How to just get the last in a recursive query
Date: Tue, 5 Apr 2022 00:21:52 +0100
Message-ID: <CA+i5JwZR_XYcbU_bekoAo1rAE=6+X+je_7+4+repLztLZqxoHg@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
References: <CA+i5JwbAz1nO_yVtfBfDeJwk8NmEQ_8bC15cOEMyc_j_Zi70Jg@mail.gmail.com>
	<CA+i5Jwbh6Yy-zW3AX3WLCUJANky9w8HtVo99NPxMAc9APY0zhw@mail.gmail.com>
	<[email protected]>

That is not the most efficient in this case.
How to tell query to deliberately miss out all except the last one is of
interest.
Regards, David

On Monday, 4 April 2022, Rob Sargent <[email protected]> wrote:

> On 4/4/22 16:14, Shaozhong SHI wrote:
>
>
>
> ---------- Forwarded message ---------
> From: Shaozhong SHI <[email protected]>
> Date: Mon, 4 Apr 2022 at 23:13
> Subject: How to just get the last in a recursive query
> To: PostGIS Users Discussion <[email protected]>
>
>
> 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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