Fix HTML markup and add NULL sorting item to existing NULL FAQ item.

Greg Sabino Mullan
21 years ago · 026a8510a3
parent d2557833e9
commit 026a8510a3
2 changed files with 59 additions and 25 deletions
--- a/doc/FAQ
+++ b/doc/FAQ
@ -1,7 +1,7 @@

                Frequently Asked Questions (FAQ) for PostgreSQL
                                       
-   Last updated: Mon Feb 14 23:35:09 EST 2005
+   Last updated: Thu Feb 24 19:32:04 EST 2005
   
   Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
   
@ -59,7 +59,8 @@
   4.8) How do I perform regular expression searches and case-insensitive
   regular expression searches? How do I use an index for
   case-insensitive searches?
-   4.9) In a query, how do I detect if a field is NULL?
+   4.9) In a query, how do I detect if a field is NULL? How can I sort on
+   whether a field is NULL or not?
   4.10) What is the difference between the various character types?
   4.11.1) How do I create a serial/auto-incrementing field?
   4.11.2) How do I get the value of a SERIAL insert?
@ -119,7 +120,8 @@
   PostgreSQL Data Base Management System
   
   Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
-   Portions Copyright (c) 1994-6 Regents of the University of California
+   Portions Copyright (c) 1994-1996 Regents of the University of
+   California
   
   Permission to use, copy, modify, and distribute this software and its
   documentation for any purpose, without fee, and without a written
@ -160,7 +162,8 @@
    1.4) Where can I get PostgreSQL?
    
   The primary anonymous ftp site for PostgreSQL is
-   ftp://ftp.PostgreSQL.org/pub. For mirror sites, see our main web site.
+   ftp://ftp.PostgreSQL.org/pub/. For mirror sites, see our main web
+   site.
   
    1.5) Where can I get support?
    
@ -177,14 +180,14 @@
   EFNet.
   
   A list of commercial support companies is available at
-   http://techdocs.postg resql.org/companies.php.
+   http://techdocs.postgresql.org/companies.php.
   
    1.6) How do I submit a bug report?
    
   Visit the PostgreSQL bug form at
   http://www.postgresql.org/support/submitbug.
   
-   Also check out our ftp site ftp://ftp.PostgreSQL.org/pub to see if
+   Also check out our ftp site ftp://ftp.PostgreSQL.org/pub/ to see if
   there is a more recent PostgreSQL version.
   
    1.7) What is the latest release?
@ -318,15 +321,15 @@
   For Web integration, PHP (http://www.php.net) is an excellent
   interface.
   
-   For complex cases, many use the Perl and CGI.pm or mod_perl.
+   For complex cases, many use the Perl DBD::Pg with CGI.pm or mod_perl.
   
    2.3) Does PostgreSQL have a graphical user interface?
    
   Yes, there are several graphical interfaces to PostgreSQL available.
   These include pgAdmin III (http://www.pgadmin.org, PgAccess
-   http://www.pgaccess.org), RHDB Admin (http://sources.redhat.com/rhd b/
-   ), TORA (http://www.globecom.net/tora/, partly commercial), and Rekall
-   ( http://www.rekallrevealed.org/). There is also PhpPgAdmin (
+   http://www.pgaccess.org), RHDB Admin (http://sources.redhat.com/rhdb/
+   ), TORA ( http://www.globecom.net/tora/, partly commercial), and
+   Rekall ( http://www.rekallrevealed.org/). There is also PhpPgAdmin (
   http://phppgadmin.sourceforge.net/ ), a web-based interface to
   PostgreSQL.
   
@ -634,10 +637,22 @@
   expresssion index, it will be used:
    CREATE INDEX tabindex ON tab (lower(col));

-    4.9) In a query, how do I detect if a field is NULL?
+    4.9) In a query, how do I detect if a field is NULL? How can I sort on
+    whether a field is NULL or not?
    
   You test the column with IS NULL and IS NOT NULL.
-   
+   SELECT *
+   FROM tab
+   WHERE col IS NULL;
+
+   To sort by the NULLIS NULL
+   and IS NOT NULL modifiers in your WHERE clause. Things that are true
+   will sort higher than things that are false, so the following will put
+   NULL entries at the top of the resulting list:
+   SELECT *
+   FROM tab
+   ORDER BY (col IS NOT NULL)
+
    4.10) What is the difference between the various character types?
    
        Type    Internal Name                    Notes
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@ -10,7 +10,7 @@
  alink="#0000ff">
    <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>

-    <P>Last updated: Mon Feb 14 23:35:09 EST 2005</P>
+    <P>Last updated: Thu Feb 24 19:32:04 EST 2005</P>

    <P>Current maintainer: Bruce Momjian (<A href=
    "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)
@ -85,7 +85,8 @@
    searches and case-insensitive regular expression searches? How do I
    use an index for case-insensitive searches?<BR>
     <A href="#4.9">4.9</A>) In a query, how do I detect if a field
-    is <SMALL>NULL</SMALL>?<BR>
+    is <SMALL>NULL</SMALL>?  How can I sort on whether a field is <SMALL>
+    NULL</SMALL> or not?<BR>
     <A href="#4.10">4.10</A>) What is the difference between the
    various character types?<BR>
     <A href="#4.11.1">4.11.1</A>) How do I create a
@ -162,7 +163,7 @@
    <P>PostgreSQL Data Base Management System</P>

    <P>Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
-    Portions Copyright (c) 1994-6 Regents of the University of California</P>
+    Portions Copyright (c) 1994-1996 Regents of the University of California</P>

    <P>Permission to use, copy, modify, and distribute this software
    and its documentation for any purpose, without fee, and without a
@ -206,7 +207,7 @@
    <H4><A name="1.4">1.4</A>) Where can I get PostgreSQL?</H4>

    <P>The primary anonymous ftp site for PostgreSQL is <A href=
-    "ftp://ftp.PostgreSQL.org/pub">ftp://ftp.PostgreSQL.org/pub</A>.
+    "ftp://ftp.PostgreSQL.org/pub/">ftp://ftp.PostgreSQL.org/pub/</A>.
    For mirror sites, see our main web site.</P>

    <H4><A name="1.5">1.5</A>) Where can I get support?</H4>
@ -225,8 +226,8 @@
    (<I>#postgresqlfr</I>).  There is also a PostgreSQL channel on EFNet.

    <P>A list of commercial support companies is available at <A href=
-    "http://techdocs.postgresql.org/companies.php">http://techdocs.postg
-    resql.org/companies.php</A>.</P>
+    "http://techdocs.postgresql.org/companies.php">
+    http://techdocs.postgresql.org/companies.php</A>.</P>

    <H4><A name="1.6">1.6</A>) How do I submit a bug report?</H4>

@ -235,7 +236,7 @@
    http://www.postgresql.org/support/submitbug</A>.</P>

    <P>Also check out our ftp site <A href=
-    "ftp://ftp.PostgreSQL.org/pub">ftp://ftp.PostgreSQL.org/pub</A> to
+    "ftp://ftp.PostgreSQL.org/pub/">ftp://ftp.PostgreSQL.org/pub/</A> to
    see if there is a more recent PostgreSQL version.</P>

    <H4><A name="1.7">1.7</A>) What is the latest release?</H4>
@ -411,7 +412,8 @@
    href="http://www.php.net">http://www.php.net</A>) is an excellent
    interface.</P>

-    <P>For complex cases, many use the Perl and CGI.pm or mod_perl.</P>
+    <P>For complex cases, many use the Perl DBD::Pg with CGI.pm or
+    mod_perl.</P>

    <H4><A name="2.3">2.3</A>) Does PostgreSQL have a graphical user
    interface?</H4>
@ -421,10 +423,9 @@
    href="http://www.pgadmin.org">http://www.pgadmin.org</a>, PgAccess
    <a href="http://www.pgaccess.org"> http://www.pgaccess.org</a>),
    RHDB Admin (<a
-    href="http://sources.redhat.com/rhdb/">http://sources.redhat.com/rhd
-    b/ </a>), TORA (<a
-    href="http://www.globecom.net/tora/">http://www.globecom.net/tora/</a>, 
-    partly commercial), and Rekall (<a
+    href="http://sources.redhat.com/rhdb/">http://sources.redhat.com/rhdb/
+    </a>), TORA (<a href="http://www.globecom.net/tora/">
+    http://www.globecom.net/tora/</a>, partly commercial), and Rekall (<a
    href="http://www.rekallrevealed.org/">
    http://www.rekallrevealed.org/</a>). There is also PhpPgAdmin (<a
    href="http://phppgadmin.sourceforge.net/">
@ -815,11 +816,29 @@ table?</TD><TD>unlimited</TD></TR>
 </PRE>

    <H4><A name="4.9">4.9</A>) In a query, how do I detect if a field
-    is <SMALL>NULL</SMALL>?</H4>
+    is <SMALL>NULL</SMALL>?  How can I sort on whether a field is <SMALL>
+    NULL</SMALL> or not?</H4>

    <P>You test the column with <SMALL>IS NULL</SMALL> and <SMALL>IS
    NOT NULL</SMALL>.</P>

+<PRE>
+   SELECT *
+   FROM tab
+   WHERE col IS NULL;
+</PRE>
+
+   <P>To sort by the <SMALL>NULL</SMALL status, use the <SMALL>IS NULL</SMALL>
+   and <SMALL>IS NOT NULL</SMALL> modifiers in your <SMALL>WHERE</SMALL> clause.
+   Things that are <I>true</I> will sort higher than things that are <I>false</I>,
+   so the following will put NULL entries at the top of the resulting list:</P>
+
+<PRE>
+   SELECT *
+   FROM tab
+   ORDER BY (col IS NOT NULL)
+</PRE>
+
    <H4><A name="4.10">4.10</A>) What is the difference between the
    various character types?</H4>
 <BLOCKQUOTE>