From b997a4b91f51ffbde42aea777d3cea6df58746c4 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Tue, 20 Jun 2000 18:04:18 +0000
Subject: [PATCH] > Great! Please cc: the docs or hackers mailing lists to make
sure the > patches are not lost...
Aggregate doc patches:
The patches are attached. Be great if you could check them over to make
sure all relevant content (and markup) is there...
Isaac Wilcox
---
doc/src/sgml/func.sgml | 81 ++++++++++++++++++++++++++++++++++++++++
doc/src/sgml/sql.sgml | 4 +-
doc/src/sgml/syntax.sgml | 4 +-
3 files changed, 85 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 3b50375e160..0023a28b0aa 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1515,6 +1515,87 @@ Not defined by this name. Implements the intersection operator '#'
</sect1>
+ <sect1>
+
+ <title id="aggregate-funcs">Aggregate Functions</title>
+
+ <note>
+ <title>Author</title>
+ <para>
+ Written by <ulink url="mailto:isaac@azartmedia.com">Isaac Wilcox</ulink>
+ on 2000-06-16.
+ </para>
+ </note>
+
+ <para>
+ <firstterm>Aggregate functions</firstterm> allow the generation of simple
+ statistics about the values of particular columns over the selected set
+ of rows. See also <xref linkend="sql" endterm="aggregates-tutorial"> and
+ <xref linkend="syntax" endterm="aggregates-syntax">.
+ </para>
+
+ <para>
+ <table tocentry="1">
+ <title>Aggregate Functions</title>
+ <tgroup cols="4">
+ <thead>
+ <row>
+ <entry>Function</entry>
+ <entry>Returns</entry>
+ <entry>Description</entry>
+ <entry>Example</entry>
+ <entry>Notes</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>COUNT(*)</entry>
+ <entry>int4</entry>
+ <entry>Counts the selected rows.</entry>
+ <entry>COUNT(*)</entry>
+ <entry></entry>
+ </row>
+ <row>
+ <entry>COUNT(<replaceable class="parameter">column-name</replaceable>)</entry>
+ <entry>int4</entry>
+ <entry>Counts the selected rows for which the value of <replaceable class="parameter">column-name</replaceable> is not NULL.</entry>
+ <entry>COUNT(age)</entry>
+ <entry></entry>
+ </row>
+ <row>
+ <entry>SUM(<replaceable class="parameter">column-name</replaceable>)</entry>
+ <entry>Same as the data type of the column being summed.</entry>
+ <entry>Finds the total obtained by adding the values of <replaceable class="parameter">column-name</replaceable> across all selected rows.</entry>
+ <entry>SUM(hours)</entry>
+ <entry>Summation is supported on the following data types: int8, int4, int2, float4, float8, money, interval, numeric</entry>
+ </row>
+ <row>
+ <entry>MAX(<replaceable class="parameter">column-name</replaceable>)</entry>
+ <entry>Same as the data type of the column whose maximum value is sought.</entry>
+ <entry>The maximum value of <replaceable class="parameter">column-name</replaceable> across all selected rows.</entry>
+ <entry>MAX(age)</entry>
+ <entry>Finding the maximum value is supported on the following data types: int8, int4, int2, float4, float8, date, time, timetz, money, timestamp, interval, text, numeric.</entry>
+ </row>
+ <row>
+ <entry>MIN(<replaceable class="parameter">column-name</replaceable>)</entry>
+ <entry>same as the data type of the column whose minimum value is sought.</entry>
+ <entry>The minimum value of <replaceable class="parameter">column-name</replaceable> across all selected rows.</entry>
+ <entry>MIN(age)</entry>
+ <entry>Finding the minimum value is supported on the following data types: int8, int4, int2, float4, float8, date, time, timetz, money, timestamp, interval, text, numeric.</entry>
+ </row>
+ <row>
+ <entry>AVG(<replaceable class="parameter">column-name</replaceable>)</entry>
+ <entry>Same as the data type of the column being averaged.</entry>
+ <entry>The average (mean) of the values in the given column across all selected rows.</entry>
+ <entry>AVG(age)</entry>
+ <entry>Finding the mean value is supported on the following data types: int8, int4, int2, float4, float8, money, interval, numeric. Note that as the return type is the same as that of the data being averaged, using AVG() on discrete data will give a rounded result.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </para>
+ </sect1>
+
</chapter>
<!-- Keep this comment at the end of the file
diff --git a/doc/src/sgml/sql.sgml b/doc/src/sgml/sql.sgml
index 054b2fba730..05d6442fbb0 100644
--- a/doc/src/sgml/sql.sgml
+++ b/doc/src/sgml/sql.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.10 2000/06/14 13:10:48 thomas Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.11 2000/06/20 18:04:18 momjian Exp $
-->
<chapter id="sql">
@@ -1032,7 +1032,7 @@ SELECT S.SNAME, P.PNAME
</sect3>
<sect3>
- <title>Aggregate Operators</title>
+ <title id="aggregates-tutorial">Aggregate Operators</title>
<para>
<acronym>SQL</acronym> provides aggregate operators
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index f07da189173..6c9ccaf45e5 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.21 2000/06/09 01:43:56 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.22 2000/06/20 18:04:18 momjian Exp $
-->
<chapter id="syntax">
@@ -747,7 +747,7 @@ sqrt(emp.salary)
</sect2>
<sect2>
- <title>Aggregate Expressions</title>
+ <title id="aggregates-syntax">Aggregate Expressions</title>
<para>
An <firstterm>aggregate expression</firstterm> represents the application
--
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