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Postgres FD Implementation
Commit c3641483 authored by Peter Eisentraut's avatar Peter Eisentraut
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Merge functions and operators chapters. Lots of updates.

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doc/src/sgml/Makefile
View file @ c3641483
......@@ -8,7 +8,7 @@
#
#
# IDENTIFICATION
# $Header: /cvsroot/pgsql/doc/src/sgml/Makefile,v 1.26 2000/11/24 17:44:21 petere Exp $
# $Header: /cvsroot/pgsql/doc/src/sgml/Makefile,v 1.27 2000/12/14 22:30:56 petere Exp $
#
#----------------------------------------------------------------------------
......@@ -16,6 +16,7 @@ subdir = doc/src/sgml
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
.SECONDARY:
ifndef DOCBOOKSTYLE
DOCBOOKSTYLE = /home/projects/pgsql/developers/thomas/db143.d/docbook
......
doc/src/sgml/datatype.sgml
View file @ c3641483
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.43 2000/12/03 14:47:18 thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.44 2000/12/14 22:30:56 petere Exp $
-->
<chapter id="datatype">
......@@ -349,8 +349,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.43 2000/12/03 14:47:18 th
<para>
The numeric types have a full set of corresponding arithmetic operators and
functions. Refer to <xref linkend="numerical-operators">
and <xref linkend="math-functions"> for more information.
functions. Refer to <xref linkend="functions"> for more information.
</para>
<para>
......
doc/src/sgml/filelist.sgml
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<!-- $Header: /cvsroot/pgsql/doc/src/sgml/filelist.sgml,v 1.1 2000/11/24 17:44:21 petere Exp $ -->
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/filelist.sgml,v 1.2 2000/12/14 22:30:56 petere Exp $ -->
<!entity about SYSTEM "about.sgml">
<!entity history SYSTEM "history.sgml">
......@@ -26,7 +26,6 @@
<!entity inherit SYSTEM "inherit.sgml">
<!entity manage SYSTEM "manage.sgml">
<!entity mvcc SYSTEM "mvcc.sgml">
<!entity oper SYSTEM "oper.sgml">
<!entity plan SYSTEM "plan.sgml">
<!entity plperl SYSTEM "plperl.sgml">
<!entity plsql SYSTEM "plsql.sgml">
......
doc/src/sgml/func.sgml
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doc/src/sgml/oper.sgml deleted 100644 → 0
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doc/src/sgml/syntax.sgml
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<!--
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.25 2000/09/29 20:21:34 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.26 2000/12/14 22:30:56 petere Exp $
-->
<chapter id="syntax">
......@@ -656,7 +656,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> )
<para>
Any built-in system, or user-defined operator may be used in SQL.
For the list of built-in and system operators consult
<xref linkend="operators" endterm="operators-title">.
<xref linkend="functions">.
For a list of user-defined operators consult your system administrator
or run a query on the <literal>pg_operator</literal> class.
Parentheses may be used for arbitrary grouping of operators in expressions.
......@@ -669,10 +669,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> )
<para>
<acronym>SQL92</acronym> allows <firstterm>expressions</firstterm>
to transform data in tables. Expressions may contain operators
(see <xref linkend="operators" endterm="operators-title">
for more details) and functions
(<xref linkend="functions" endterm="functions-title"> has
more information).
and functions.
</para>
<para>
......@@ -749,8 +746,8 @@ sqrt(emp.salary)
</para>
</sect2>
<sect2>
<title id="aggregates-syntax">Aggregate Expressions</title>
<sect2 id="syntax-aggregates">
<title>Aggregate Expressions</title>
<para>
An <firstterm>aggregate expression</firstterm> represents the application
......@@ -863,6 +860,177 @@ sqrt(emp.salary)
before the classname.
</para>
</sect2>
<sect2 id="sql-precedence">
<title>Lexical Precedence</title>
<para>
The precedence and associativity of the operators is hard-wired
into the parser. Most operators have the same precedence and are
left-associative. This may lead to non-intuitive behavior; for
example the boolean operators "&lt;" and "&gt;" have a different
precedence than the boolean operators "&lt;=" and "&gt;=". Also,
you will sometimes need to add parenthesis when using combinations
of binary and unary operators. For instance
<programlisting>
SELECT 5 &amp; ~ 6;
</programlisting>
will be parsed as
<programlisting>
SELECT (5 &amp;) ~ 6;
</programlisting>
because the parser has no idea that <token>&amp;</token> is
defined as a binary operator. This is the price one pays for
extensibility.
</para>
<table tocentry="1">
<title>Operator Ordering (decreasing precedence)</title>
<tgroup cols="2">
<thead>
<row>
<entry>OperatorElement</entry>
<entry>Associativity</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry><token>::</token></entry>
<entry>left</entry>
<entry><productname>Postgres</productname>-style typecast</entry>
</row>
<row>
<entry><token>[</token> <token>]</token></entry>
<entry>left</entry>
<entry>array element selection</entry>
</row>
<row>
<entry><token>.</token></entry>
<entry>left</entry>
<entry>table/column name separator</entry>
</row>
<row>
<entry><token>-</token></entry>
<entry>right</entry>
<entry>unary minus</entry>
</row>
<row>
<entry><token>^</token></entry>
<entry>left</entry>
<entry>exponentiation</entry>
</row>
<row>
<entry><token>*</token> <token>/</token> <token>%</token></entry>
<entry>left</entry>
<entry>multiplication, division, modulo</entry>
</row>
<row>
<entry><token>+</token> <token>-</token></entry>
<entry>left</entry>
<entry>addition, subtraction</entry>
</row>
<row>
<entry><token>IS</token></entry>
<entry></entry>
<entry>test for TRUE, FALSE, NULL</entry>
</row>
<row>
<entry><token>ISNULL</token></entry>
<entry></entry>
<entry>test for NULL</entry>
</row>
<row>
<entry><token>NOTNULL</token></entry>
<entry></entry>
<entry>test for NOT NULL</entry>
</row>
<row>
<entry>(any other)</entry>
<entry>left</entry>
<entry>all other native and user-defined operators</entry>
</row>
<row>
<entry><token>IN</token></entry>
<entry></entry>
<entry>set membership</entry>
</row>
<row>
<entry><token>BETWEEN</token></entry>
<entry></entry>
<entry>containment</entry>
</row>
<row>
<entry><token>OVERLAPS</token></entry>
<entry></entry>
<entry>time interval overlap</entry>
</row>
<row>
<entry><token>LIKE</token> <token>ILIKE</token></entry>
<entry></entry>
<entry>string pattern matching</entry>
</row>
<row>
<entry><token>&lt;</token> <token>&gt;</token></entry>
<entry></entry>
<entry>less than, greater than</entry>
</row>
<row>
<entry><token>=</token></entry>
<entry>right</entry>
<entry>equality, assignment</entry>
</row>
<row>
<entry><token>NOT</token></entry>
<entry>right</entry>
<entry>logical negation</entry>
</row>
<row>
<entry><token>AND</token></entry>
<entry>left</entry>
<entry>logical conjunction</entry>
</row>
<row>
<entry><token>OR</token></entry>
<entry>left</entry>
<entry>logical disjunction</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
Note that the operator precedence rules also apply to user-defined
operators that <quote>look like</quote> the built-in operators
with special treatment. For example, if you define a
<quote>+</quote> operator for some custom data type it will have
the same precedence as the built-in <quote>+</quote> operator, no
matter what yours does.
</para>
</sect2>
</sect1>
</chapter>
......
doc/src/sgml/user.sgml
View file @ c3641483
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/user.sgml,v 1.20 2000/11/24 17:44:22 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/user.sgml,v 1.21 2000/12/14 22:30:56 petere Exp $
-->
<book id="user">
......@@ -45,11 +45,10 @@ $Header: /cvsroot/pgsql/doc/src/sgml/Attic/user.sgml,v 1.20 2000/11/24 17:44:22
&intro;
&syntax;
&datatype;
&oper;
&func;
&typeconv;
&indices;
&array;
&indices;
&inherit;
&plsql;
&pltcl;
......
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