Received: from localhost (maia-4.hub.org [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id A97639FB54D for ; Mon, 7 May 2007 05:07:09 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 21995-07 for ; Mon, 7 May 2007 05:07:04 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.5 Received: from bay0-omc2-s24.bay0.hotmail.com (bay0-omc2-s24.bay0.hotmail.com [65.54.246.160]) by postgresql.org (Postfix) with ESMTP id 8FF119FB4CC for ; Mon, 7 May 2007 05:07:04 -0300 (ADT) Received: from hotmail.com ([64.4.53.52]) by bay0-omc2-s24.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Mon, 7 May 2007 01:07:02 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 7 May 2007 01:07:02 -0700 Message-ID: Received: from 69.45.64.75 by by19fd.bay19.hotmail.msn.com with HTTP; Mon, 07 May 2007 08:07:00 GMT X-Originating-IP: [203.125.54.38] X-Originating-Email: [ntuser155@hotmail.com] X-Sender: ntuser155@hotmail.com From: "Nemo Terry" To: pgsql-sql@postgresql.org Subject: How to use function PointN? Date: Mon, 07 May 2007 16:07:00 +0800 Mime-Version: 1.0 Content-Type: text/plain; charset=gb2312; format=flowed X-OriginalArrivalTime: 07 May 2007 08:07:02.0727 (UTC) FILETIME=[B1D6C570:01C7907E] X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=1.482 tagged_above=0 required=5 tests=AWL=-0.427, BAYES_50=0.001, DNS_FROM_RFC_ABUSE=0.2, DNS_FROM_RFC_POST=1.708, MSGID_FROM_MTA_HEADER=0 X-Spam-Level: * X-Archive-Number: 200705/39 X-Sequence-Number: 28320 select PointN(envelope(polyline),1) from highway; return null,why? _________________________________________________________________ 享用世界上最大的电子邮件系统— MSN Hotmail。 http://www.hotmail.com