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Postgres FD Implementation
Commit 95e3cec6 authored by Thomas G. Lockhart's avatar Thomas G. Lockhart
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Include mention of CASE, COALESCE, and IFNULL. 

Add date/time parsing procedure (perhaps should be in appendix).
Add time zone information (ditto).
Update keyword list.
parent 5dd715b5
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doc/src/sgml/admin.sgml
View file @ 95e3cec6
<!-- <!--
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/admin.sgml,v 1.11 1999/05/04 02:16:57 thomas Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/Attic/admin.sgml,v 1.12 1999/05/12 07:32:42 thomas Exp $
Postgres Administrator's Guide. Postgres Administrator's Guide.
Derived from postgres.sgml. Derived from postgres.sgml.
- thomas 1998-10-27 - thomas 1998-10-27
$Log: admin.sgml,v $ $Log: admin.sgml,v $
Revision 1.11 1999/05/04 02:16:57 thomas Revision 1.12 1999/05/12 07:32:42 thomas
Include chapter on security. Include mention of CASE, COALESCE, and IFNULL.
Add date/time parsing procedure (perhaps should be in appendix).
Add time zone information (ditto).
Update keyword list.
Revision 1.10 1999/01/19 16:06:25 thomas Revision 1.10 1999/01/19 16:06:25 thomas
Merge current.sgml into release.sgml so all release notes are in the same Merge current.sgml into release.sgml so all release notes are in the same
...@@ -59,8 +62,8 @@ Bigger updates to the installation instructions (install and config). ...@@ -59,8 +62,8 @@ Bigger updates to the installation instructions (install and config).
<!-- Title information --> <!-- Title information -->
<Title>PostgreSQL Administrator's Guide</Title> <Title>PostgreSQL Administrator's Guide</Title>
<BookInfo> <BookInfo>
<ReleaseInfo>Covering v6.4 for general release</ReleaseInfo> <ReleaseInfo>Covering v6.4 for general release</ReleaseInfo>
<BookBiblio> <BookBiblio>
<AuthorGroup> <AuthorGroup>
...@@ -84,17 +87,17 @@ Bigger updates to the installation instructions (install and config). ...@@ -84,17 +87,17 @@ Bigger updates to the installation instructions (install and config).
<AuthorInitials>TGL</AuthorInitials> <AuthorInitials>TGL</AuthorInitials>
--> -->
<Date>(last updated 1998-10-27)</Date> <Date>(last updated 1999-04-08)</Date>
</BookBiblio> </BookBiblio>
<LegalNotice> <LegalNotice>
<Para> <Para>
<ProductName>PostgreSQL</ProductName> is copyright (C) 1998 <ProductName>PostgreSQL</ProductName> is copyright (C) 1998-9
by the Postgres Global Development Group. by the Postgres Global Development Group.
</Para> </Para>
</LegalNotice> </LegalNotice>
</BookInfo> </BookInfo>
<!-- <!--
<TOC> </TOC> <TOC> </TOC>
...@@ -109,36 +112,36 @@ Your name here... ...@@ -109,36 +112,36 @@ Your name here...
</Dedication> </Dedication>
--> -->
<Preface id="preface"> <Preface id="preface">
<Title>Summary</Title> <Title>Summary</Title>
<Para> <Para>
<ProductName>Postgres</ProductName>, <ProductName>Postgres</ProductName>,
developed originally in the UC Berkeley Computer Science Department, developed originally in the UC Berkeley Computer Science Department,
pioneered many of the object-relational concepts pioneered many of the object-relational concepts
now becoming available in some commercial databases. now becoming available in some commercial databases.
It provides SQL92/SQL3 language support, It provides SQL92/SQL3 language support,
transaction integrity, and type extensibility. transaction integrity, and type extensibility.
<ProductName>PostgreSQL</ProductName> is a public-domain, open source descendant <ProductName>PostgreSQL</ProductName> is a public-domain, open source descendant
of this original Berkeley code. of this original Berkeley code.
</Para> </Para>
</Preface> </Preface>
&intro-ag; &intro-ag;
&ports; &ports;
&config; &config;
&install; &install;
&installw; &installw;
&runtime; &runtime;
&security; &security;
&options; &options;
&start-ag; &start-ag;
&recovery; &recovery;
&regress; &regress;
&release; &release;
&biblio; &biblio;
<!-- <!--
Don't bother with an index until we get some index entries. Don't bother with an index until we get some index entries.
......
doc/src/sgml/biblio.sgml
View file @ 95e3cec6
...@@ -2,7 +2,8 @@ ...@@ -2,7 +2,8 @@
<title>Bibliography</title> <title>Bibliography</title>
<para> <para>
Selected references and readings for <acronym>SQL</acronym> and <productname>Postgres</productname>. Selected references and readings for <acronym>SQL</acronym>
and <productname>Postgres</productname>.
</para> </para>
<bibliodiv> <bibliodiv>
......
doc/src/sgml/datatype.sgml
View file @ 95e3cec6
<chapter id="datatype"> <chapter id="datatype">
<title>Data Types</title> <title>Data Types</title>
<abstract> <abstract>
<para> <para>
Describes the built-in data types available in Describes the built-in data types available in
<productname>Postgres</productname>. <productname>Postgres</productname>.
</para> </para>
</abstract> </abstract>
<para> <para>
<productname>Postgres</productname> has a rich set of native data <productname>Postgres</productname> has a rich set of native data
types available to users. types available to users.
Users may add new types to <productname>Postgres</productname> using the Users may add new types to <productname>Postgres</productname> using the
<command>DEFINE TYPE</command> <command>DEFINE TYPE</command>
command described elsewhere. command described elsewhere.
</para> </para>
<para> <para>
In the context of data types, the following sections will discuss In the context of data types, the following sections will discuss
<acronym>SQL</acronym> standards compliance, porting issues, and usage. <acronym>SQL</acronym> standards compliance, porting issues, and usage.
Some <productname>Postgres</productname> types correspond directly to Some <productname>Postgres</productname> types correspond directly to
<acronym>SQL92</acronym>-compatible types. In other <acronym>SQL92</acronym>-compatible types. In other
cases, data types defined by <acronym>SQL92</acronym> syntax are mapped directly cases, data types defined by <acronym>SQL92</acronym> syntax are mapped directly
into native <productname>Postgres</productname> types. into native <productname>Postgres</productname> types.
Many of the built-in types have obvious external formats. However, several Many of the built-in types have obvious external formats. However, several
types are either unique to <productname>Postgres</productname>, types are either unique to <productname>Postgres</productname>,
such as open and closed paths, or have such as open and closed paths, or have
several possibilities for formats, such as the date and time types. several possibilities for formats, such as the date and time types.
</para> </para>
<para> <para>
<table tocentry="1"> <table tocentry="1">
<title><productname>Postgres</productname> Data Types</title> <title><productname>Postgres</productname> Data Types</title>
<titleabbrev>Data Types</titleabbrev> <titleabbrev>Data Types</titleabbrev>
<tgroup cols="3"> <tgroup cols="3">
<thead> <thead>
<row> <row>
<entry><productname>Postgres</productname> Type</entry> <entry><productname>Postgres</productname> Type</entry>
<entry><acronym>SQL92</acronym> or <acronym>SQL3</acronym> Type</entry> <entry><acronym>SQL92</acronym> or <acronym>SQL3</acronym> Type</entry>
<entry>Description</entry> <entry>Description</entry>
</row> </row>
</thead> </thead>
<tbody> <tbody>
<row> <row>
<entry>bool</entry> <entry>bool</entry>
<entry>boolean</entry> <entry>boolean</entry>
...@@ -169,32 +169,32 @@ several possibilities for formats, such as the date and time types. ...@@ -169,32 +169,32 @@ several possibilities for formats, such as the date and time types.
<entry>character varying(n)</entry> <entry>character varying(n)</entry>
<entry>variable-length character string</entry> <entry>variable-length character string</entry>
</row> </row>
</tbody> </tbody>
</tgroup> </tgroup>
</table> </table>
</para> </para>
<para> <para>
<note> <note>
<para> <para>
The <type>cidr</type> and <type>inet</type> types are designed to handle any IP type The <type>cidr</type> and <type>inet</type> types are designed to handle any IP type
but only ipv4 is handled in the current implementation. but only ipv4 is handled in the current implementation.
Everything here that talks about ipv4 will apply to ipv6 in a future release.</para> Everything here that talks about ipv4 will apply to ipv6 in a future release.</para>
</note></para> </note></para>
<para> <para>
<table tocentry="1"> <table tocentry="1">
<title><productname>Postgres</productname> Function Constants</title> <title><productname>Postgres</productname> Function Constants</title>
<titleabbrev>Constants</titleabbrev> <titleabbrev>Constants</titleabbrev>
<tgroup cols="3"> <tgroup cols="3">
<thead> <thead>
<row> <row>
<entry><productname>Postgres</productname> Function</entry> <entry><productname>Postgres</productname> Function</entry>
<entry><acronym>SQL92</acronym> Constant</entry> <entry><acronym>SQL92</acronym> Constant</entry>
<entry>Description</entry> <entry>Description</entry>
</row> </row>
</thead> </thead>
<tbody> <tbody>
<row> <row>
<entry>getpgusername()</entry> <entry>getpgusername()</entry>
<entry>current_user</entry> <entry>current_user</entry>
...@@ -215,57 +215,57 @@ Everything here that talks about ipv4 will apply to ipv6 in a future release.</p ...@@ -215,57 +215,57 @@ Everything here that talks about ipv4 will apply to ipv6 in a future release.</p
<entry>current_timestamp</entry> <entry>current_timestamp</entry>
<entry>date and time of current transaction</entry> <entry>date and time of current transaction</entry>
</row> </row>
</tbody> </tbody>
</tgroup> </tgroup>
</table> </table>
</para> </para>
<para> <para>
<productname>Postgres</productname> has features at the forefront of <productname>Postgres</productname> has features at the forefront of
<acronym>ORDBMS</acronym> development. In addition to <acronym>ORDBMS</acronym> development. In addition to
<acronym>SQL3</acronym> conformance, substantial portions <acronym>SQL3</acronym> conformance, substantial portions
of <acronym>SQL92</acronym> are also supported. of <acronym>SQL92</acronym> are also supported.
Although we strive for <acronym>SQL92</acronym> compliance, Although we strive for <acronym>SQL92</acronym> compliance,
there are some aspects of the standard there are some aspects of the standard
which are ill considered and which should not live through subsequent standards. which are ill considered and which should not live through subsequent standards.
<productname>Postgres</productname> will not make great efforts to <productname>Postgres</productname> will not make great efforts to
conform to these features; however, these tend to apply in little-used conform to these features; however, these tend to apply in little-used
or obsure cases, and a typical user is not likely to run into them.</para> or obsure cases, and a typical user is not likely to run into them.</para>
<para> <para>
Most of the input and output functions corresponding to the Most of the input and output functions corresponding to the
base types (e.g., integers and floating point numbers) do some base types (e.g., integers and floating point numbers) do some
error-checking. error-checking.
Some of the operators and functions (e.g., Some of the operators and functions (e.g.,
addition and multiplication) do not perform run-time error-checking in the addition and multiplication) do not perform run-time error-checking in the
interests of improving execution speed. interests of improving execution speed.
On some systems, for example, the numeric operators for some data types may On some systems, for example, the numeric operators for some data types may
silently underflow or overflow. silently underflow or overflow.
</para> </para>
<para> <para>
Note that some of the input and output functions are not invertible. That is, Note that some of the input and output functions are not invertible. That is,
the result of an output function may lose precision when compared to the result of an output function may lose precision when compared to
the original input. the original input.
<note> <note>
<para> <para>
The original <productname>Postgres</productname> v4.2 code received from The original <productname>Postgres</productname> v4.2 code received from
Berkeley rounded all double precision floating point results to six digits for Berkeley rounded all double precision floating point results to six digits for
output. Starting with v6.1, floating point numbers are allowed to retain output. Starting with v6.1, floating point numbers are allowed to retain
most of the intrinsic precision of the type (typically 15 digits for doubles, most of the intrinsic precision of the type (typically 15 digits for doubles,
6 digits for 4-byte floats). 6 digits for 4-byte floats).
Other types with underlying floating point fields (e.g. geometric Other types with underlying floating point fields (e.g. geometric
types) carry similar precision.</para> types) carry similar precision.</para>
</note> </note>
</para> </para>
<sect1> <sect1>
<title>Numeric Types</title> <title>Numeric Types</title>
<para> <para>
Numeric types consist of two- and four-byte integers and four- and eight-byte Numeric types consist of two- and four-byte integers and four- and eight-byte
floating point numbers.</para> floating point numbers.</para>
<para> <para>
<table tocentry="1"> <table tocentry="1">
......
doc/src/sgml/func.sgml
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<Chapter Id="functions"> <Chapter Id="functions">
<Title>Functions</Title> <Title id="functions-title">Functions</Title>
<Abstract> <Abstract>
<Para> <Para>
Describes the built-in functions available in <ProductName>Postgres</ProductName>. Describes the built-in functions available in <ProductName>Postgres</ProductName>.
</Para> </Para>
</Abstract> </Abstract>
<Para>
Many data types have functions available for conversion to other related types.
In addition, there are some type-specific functions. Some functions are also
available through operators and may be documented as operators only.
</Para>
<sect1>
<title id="sql-funcs">SQL Functions</title>
<para>
<quote><acronym>SQL</acronym> functions</quote> are constructs
defined by the <acronym>SQL92</acronym> standard which have
function-like syntax but which can not be implemented as simple
functions.
</para>
<Para> <para>
Many data types have functions available for conversion to other related types. <TABLE TOCENTRY="1">
In addition, there are some type-specific functions. Some functions are also <TITLE>SQL Functions</TITLE>
available through operators and may be documented as operators only. <TGROUP COLS="4">
</Para> <THEAD>
<ROW>
<ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY>
</ROW>
</THEAD>
<TBODY>
<ROW>
<ENTRY> COALESCE(<replaceable class="parameter">list</replaceable>) </ENTRY>
<ENTRY> non-NULL </ENTRY>
<ENTRY> return first non-NULL value in list </ENTRY>
<ENTRY> COALESCE(<replaceable class="parameter">c1</replaceable>, <replaceable class="parameter">c2</replaceable> + 5, 0) </ENTRY>
</ROW>
<ROW>
<ENTRY> IFNULL(<replaceable
class="parameter">input</replaceable>,<replaceable> class="parameter">non-NULL substitute</replaceable>) </ENTRY>
<ENTRY> non-NULL </ENTRY>
<ENTRY> return second argument if first is NULL </ENTRY>
<ENTRY> IFNULL(<replaceable class="parameter">c1</replaceable>, 'N/A')</ENTRY>
</ROW>
<ROW>
<ENTRY> CASE(WHEN <replaceable class="parameter">expr</replaceable> THEN <replaceable class="parameter">expr</replaceable> [...] ELSE <replaceable class="parameter">expr</replaceable> ) </ENTRY>
<ENTRY> <replaceable class="parameter">expr</replaceable> </ENTRY>
<ENTRY> return expression for first true clause </ENTRY>
<ENTRY> CASE(WHEN <replaceable class="parameter">c1</replaceable> = 1 THEN 'match' ELSE 'no match') </ENTRY>
</ROW>
</tbody>
</tgroup>
</table>
</para>
</sect1>
<sect1> <sect1>
<title id="math-funcs">Mathematical Functions</title> <title id="math-funcs">Mathematical Functions</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>Mathematical Functions</TITLE> <TITLE>Mathematical Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> dexp(float8) </ENTRY> <ENTRY> dexp(float8) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> raise e to the specified exponent </ENTRY> <ENTRY> raise e to the specified exponent </ENTRY>
<ENTRY> dexp(2.0) </ENTRY> <ENTRY> dexp(2.0) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> dpow(float8,float8) </ENTRY> <ENTRY> dpow(float8,float8) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> raise a number to the specified exponent </ENTRY> <ENTRY> raise a number to the specified exponent </ENTRY>
<ENTRY> dpow(2.0, 16.0) </ENTRY> <ENTRY> dpow(2.0, 16.0) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> float(int) </ENTRY> <ENTRY> float(int) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> convert integer to floating point </ENTRY> <ENTRY> convert integer to floating point </ENTRY>
<ENTRY> float(2) </ENTRY> <ENTRY> float(2) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> float4(int) </ENTRY> <ENTRY> float4(int) </ENTRY>
<ENTRY> float4 </ENTRY> <ENTRY> float4 </ENTRY>
<ENTRY> convert integer to floating point </ENTRY> <ENTRY> convert integer to floating point </ENTRY>
<ENTRY> float4(2) </ENTRY> <ENTRY> float4(2) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> integer(float) </ENTRY> <ENTRY> integer(float) </ENTRY>
<ENTRY> int </ENTRY> <ENTRY> int </ENTRY>
<ENTRY> convert floating point to integer </ENTRY> <ENTRY> convert floating point to integer </ENTRY>
<ENTRY> integer(2.0) </ENTRY> <ENTRY> integer(2.0) </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title>String Functions</title> <title>String Functions</title>
...@@ -146,573 +194,574 @@ available through operators and may be documented as operators only. ...@@ -146,573 +194,574 @@ available through operators and may be documented as operators only.
Some are used internally to implement the SQL92 string functions listed above. Some are used internally to implement the SQL92 string functions listed above.
</Para> </Para>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>String Functions</TITLE> <TITLE>String Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> char(text) </ENTRY> <ENTRY> char(text) </ENTRY>
<ENTRY> char </ENTRY> <ENTRY> char </ENTRY>
<ENTRY> convert text to char type </ENTRY> <ENTRY> convert text to char type </ENTRY>
<ENTRY> char('text string') </ENTRY> <ENTRY> char('text string') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> char(varchar) </ENTRY> <ENTRY> char(varchar) </ENTRY>
<ENTRY> char </ENTRY> <ENTRY> char </ENTRY>
<ENTRY> convert varchar to char type </ENTRY> <ENTRY> convert varchar to char type </ENTRY>
<ENTRY> char(varchar 'varchar string') </ENTRY> <ENTRY> char(varchar 'varchar string') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> initcap(text) </ENTRY> <ENTRY> initcap(text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> first letter of each word to upper case </ENTRY> <ENTRY> first letter of each word to upper case </ENTRY>
<ENTRY> initcap('thomas') </ENTRY> <ENTRY> initcap('thomas') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> lpad(text,int,text) </ENTRY> <ENTRY> lpad(text,int,text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> left pad string to specified length </ENTRY> <ENTRY> left pad string to specified length </ENTRY>
<ENTRY> lpad('hi',4,'??') </ENTRY> <ENTRY> lpad('hi',4,'??') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> ltrim(text,text) </ENTRY> <ENTRY> ltrim(text,text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> left trim characters from text </ENTRY> <ENTRY> left trim characters from text </ENTRY>
<ENTRY> ltrim('xxxxtrim','x') </ENTRY> <ENTRY> ltrim('xxxxtrim','x') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> textpos(text,text) </ENTRY> <ENTRY> textpos(text,text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> locate specified substring </ENTRY> <ENTRY> locate specified substring </ENTRY>
<ENTRY> position('high','ig') </ENTRY> <ENTRY> position('high','ig') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> rpad(text,int,text) </ENTRY> <ENTRY> rpad(text,int,text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> right pad string to specified length </ENTRY> <ENTRY> right pad string to specified length </ENTRY>
<ENTRY> rpad('hi',4,'x') </ENTRY> <ENTRY> rpad('hi',4,'x') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> rtrim(text,text) </ENTRY> <ENTRY> rtrim(text,text) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> right trim characters from text </ENTRY> <ENTRY> right trim characters from text </ENTRY>
<ENTRY> rtrim('trimxxxx','x') </ENTRY> <ENTRY> rtrim('trimxxxx','x') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> substr(text,int[,int]) </ENTRY> <ENTRY> substr(text,int[,int]) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> extract specified substring </ENTRY> <ENTRY> extract specified substring </ENTRY>
<ENTRY> substr('hi there',3,5) </ENTRY> <ENTRY> substr('hi there',3,5) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> text(char) </ENTRY> <ENTRY> text(char) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> convert char to text type </ENTRY> <ENTRY> convert char to text type </ENTRY>
<ENTRY> text('char string') </ENTRY> <ENTRY> text('char string') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> text(varchar) </ENTRY> <ENTRY> text(varchar) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> convert varchar to text type </ENTRY> <ENTRY> convert varchar to text type </ENTRY>
<ENTRY> text(varchar 'varchar string') </ENTRY> <ENTRY> text(varchar 'varchar string') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> translate(text,from,to) </ENTRY> <ENTRY> translate(text,from,to) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> convert character in string </ENTRY> <ENTRY> convert character in string </ENTRY>
<ENTRY> translate('12345', '1', 'a') </ENTRY> <ENTRY> translate('12345', '1', 'a') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> varchar(char) </ENTRY> <ENTRY> varchar(char) </ENTRY>
<ENTRY> varchar </ENTRY> <ENTRY> varchar </ENTRY>
<ENTRY> convert char to varchar type </ENTRY> <ENTRY> convert char to varchar type </ENTRY>
<ENTRY> varchar('char string') </ENTRY> <ENTRY> varchar('char string') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> varchar(text) </ENTRY> <ENTRY> varchar(text) </ENTRY>
<ENTRY> varchar </ENTRY> <ENTRY> varchar </ENTRY>
<ENTRY> convert text to varchar type </ENTRY> <ENTRY> convert text to varchar type </ENTRY>
<ENTRY> varchar('text string') </ENTRY> <ENTRY> varchar('text string') </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
<para> <para>
Most functions explicitly defined for text will work for char() and varchar() arguments. Most functions explicitly defined for text will work for char() and varchar() arguments.
</para> </para>
</sect1> </sect1>
<sect1> <sect1>
<title>Date/Time Functions</title> <title>Date/Time Functions</title>
<para> <para>
The date/time functions provide a powerful set of tools for manipulating various date/time types. The date/time functions provide a powerful set of tools
</para> for manipulating various date/time types.
</para>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>Date/Time Functions</TITLE> <TITLE>Date/Time Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> abstime(datetime) </ENTRY> <ENTRY> abstime(datetime) </ENTRY>
<ENTRY> abstime </ENTRY> <ENTRY> abstime </ENTRY>
<ENTRY> convert to abstime </ENTRY> <ENTRY> convert to abstime </ENTRY>
<ENTRY> abstime('now'::datetime) </ENTRY> <ENTRY> abstime('now'::datetime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> age(datetime,datetime) </ENTRY> <ENTRY> age(datetime,datetime) </ENTRY>
<ENTRY> timespan </ENTRY> <ENTRY> timespan </ENTRY>
<ENTRY> span preserving months and years </ENTRY> <ENTRY> span preserving months and years </ENTRY>
<ENTRY> age('now','1957-06-13'::datetime) </ENTRY> <ENTRY> age('now','1957-06-13'::datetime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> datetime(abstime) </ENTRY> <ENTRY> datetime(abstime) </ENTRY>
<ENTRY> datetime </ENTRY> <ENTRY> datetime </ENTRY>
<ENTRY> convert to datetime </ENTRY> <ENTRY> convert to datetime </ENTRY>
<ENTRY> datetime('now'::abstime) </ENTRY> <ENTRY> datetime('now'::abstime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> datetime(date) </ENTRY> <ENTRY> datetime(date) </ENTRY>
<ENTRY> datetime </ENTRY> <ENTRY> datetime </ENTRY>
<ENTRY> convert to datetime </ENTRY> <ENTRY> convert to datetime </ENTRY>
<ENTRY> datetime('today'::date) </ENTRY> <ENTRY> datetime('today'::date) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> datetime(date,time) </ENTRY> <ENTRY> datetime(date,time) </ENTRY>
<ENTRY> datetime </ENTRY> <ENTRY> datetime </ENTRY>
<ENTRY> convert to datetime </ENTRY> <ENTRY> convert to datetime </ENTRY>
<ENTRY> datetime('1998-02-24'::datetime, '23:07'::time); </ENTRY> <ENTRY> datetime('1998-02-24'::datetime, '23:07'::time); </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> date_part(text,datetime) </ENTRY> <ENTRY> date_part(text,datetime) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> specified portion of date field </ENTRY> <ENTRY> specified portion of date field </ENTRY>
<ENTRY> date_part('dow','now'::datetime) </ENTRY> <ENTRY> date_part('dow','now'::datetime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> date_part(text,timespan) </ENTRY> <ENTRY> date_part(text,timespan) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> specified portion of time field </ENTRY> <ENTRY> specified portion of time field </ENTRY>
<ENTRY> date_part('hour','4 hrs 3 mins'::timespan) </ENTRY> <ENTRY> date_part('hour','4 hrs 3 mins'::timespan) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> date_trunc(text,datetime) </ENTRY> <ENTRY> date_trunc(text,datetime) </ENTRY>
<ENTRY> datetime </ENTRY> <ENTRY> datetime </ENTRY>
<ENTRY> truncate date at specified units </ENTRY> <ENTRY> truncate date at specified units </ENTRY>
<ENTRY> date_trunc('month','now'::abstime) </ENTRY> <ENTRY> date_trunc('month','now'::abstime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> isfinite(abstime) </ENTRY> <ENTRY> isfinite(abstime) </ENTRY>
<ENTRY> bool </ENTRY> <ENTRY> bool </ENTRY>
<ENTRY> TRUE if this is a finite time </ENTRY> <ENTRY> TRUE if this is a finite time </ENTRY>
<ENTRY> isfinite('now'::abstime) </ENTRY> <ENTRY> isfinite('now'::abstime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> isfinite(datetime) </ENTRY> <ENTRY> isfinite(datetime) </ENTRY>
<ENTRY> bool </ENTRY> <ENTRY> bool </ENTRY>
<ENTRY> TRUE if this is a finite time </ENTRY> <ENTRY> TRUE if this is a finite time </ENTRY>
<ENTRY> isfinite('now'::datetime) </ENTRY> <ENTRY> isfinite('now'::datetime) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> isfinite(timespan) </ENTRY> <ENTRY> isfinite(timespan) </ENTRY>
<ENTRY> bool </ENTRY> <ENTRY> bool </ENTRY>
<ENTRY> TRUE if this is a finite time </ENTRY> <ENTRY> TRUE if this is a finite time </ENTRY>
<ENTRY> isfinite('4 hrs'::timespan) </ENTRY> <ENTRY> isfinite('4 hrs'::timespan) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> reltime(timespan) </ENTRY> <ENTRY> reltime(timespan) </ENTRY>
<ENTRY> reltime </ENTRY> <ENTRY> reltime </ENTRY>
<ENTRY> convert to reltime </ENTRY> <ENTRY> convert to reltime </ENTRY>
<ENTRY> reltime('4 hrs'::timespan) </ENTRY> <ENTRY> reltime('4 hrs'::timespan) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> timespan(reltime) </ENTRY> <ENTRY> timespan(reltime) </ENTRY>
<ENTRY> timespan </ENTRY> <ENTRY> timespan </ENTRY>
<ENTRY> convert to timespan </ENTRY> <ENTRY> convert to timespan </ENTRY>
<ENTRY> timespan('4 hours'::reltime) </ENTRY> <ENTRY> timespan('4 hours'::reltime) </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
<Para> <Para>
For the For the
<Function>date_part</Function> and <Function>date_trunc</Function> <Function>date_part</Function> and <Function>date_trunc</Function>
functions, arguments can be functions, arguments can be
`year', `month', `day', `hour', `minute', and `second', `year', `month', `day', `hour', `minute', and `second',
as well as the more specialized quantities as well as the more specialized quantities
`decade', `century', `millenium', `millisecond', and `microsecond'. `decade', `century', `millenium', `millisecond', and `microsecond'.
<Function>date_part</Function> allows `dow' <Function>date_part</Function> allows `dow'
to return day of week and `epoch' to return seconds since 1970 (for <Type>datetime</Type>) to return day of week and `epoch' to return seconds since 1970 (for <Type>datetime</Type>)
or 'epoch' to return total elapsed seconds (for <Type>timespan</Type>). or 'epoch' to return total elapsed seconds (for <Type>timespan</Type>).
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title>Geometric Functions</title> <title>Geometric Functions</title>
<para> <para>
The geometric types point, box, lseg, line, path, polygon, and circle have a large set of native The geometric types point, box, lseg, line, path, polygon, and
support functions. circle have a large set of native support functions.
</para> </para>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>Geometric Functions</TITLE> <TITLE>Geometric Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> area(box) </ENTRY> <ENTRY> area(box) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> area of box </ENTRY> <ENTRY> area of box </ENTRY>
<ENTRY> area('((0,0),(1,1))'::box) </ENTRY> <ENTRY> area('((0,0),(1,1))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> area(circle) </ENTRY> <ENTRY> area(circle) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> area of circle </ENTRY> <ENTRY> area of circle </ENTRY>
<ENTRY> area('((0,0),2.0)'::circle) </ENTRY> <ENTRY> area('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> box(box,box) </ENTRY> <ENTRY> box(box,box) </ENTRY>
<ENTRY> box </ENTRY> <ENTRY> box </ENTRY>
<ENTRY> boxes to intersection box </ENTRY> <ENTRY> boxes to intersection box </ENTRY>
<ENTRY> box('((0,0),(1,1))','((0.5,0.5),(2,2))') </ENTRY> <ENTRY> box('((0,0),(1,1))','((0.5,0.5),(2,2))') </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> center(box) </ENTRY> <ENTRY> center(box) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> center of object </ENTRY> <ENTRY> center of object </ENTRY>
<ENTRY> center('((0,0),(1,2))'::box) </ENTRY> <ENTRY> center('((0,0),(1,2))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> center(circle) </ENTRY> <ENTRY> center(circle) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> center of object </ENTRY> <ENTRY> center of object </ENTRY>
<ENTRY> center('((0,0),2.0)'::circle) </ENTRY> <ENTRY> center('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> diameter(circle) </ENTRY> <ENTRY> diameter(circle) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> diameter of circle </ENTRY> <ENTRY> diameter of circle </ENTRY>
<ENTRY> diameter('((0,0),2.0)'::circle) </ENTRY> <ENTRY> diameter('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> height(box) </ENTRY> <ENTRY> height(box) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> vertical size of box </ENTRY> <ENTRY> vertical size of box </ENTRY>
<ENTRY> height('((0,0),(1,1))'::box) </ENTRY> <ENTRY> height('((0,0),(1,1))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> isclosed(path) </ENTRY> <ENTRY> isclosed(path) </ENTRY>
<ENTRY> bool </ENTRY> <ENTRY> bool </ENTRY>
<ENTRY> TRUE if this is a closed path </ENTRY> <ENTRY> TRUE if this is a closed path </ENTRY>
<ENTRY> isclosed('((0,0),(1,1),(2,0))'::path) </ENTRY> <ENTRY> isclosed('((0,0),(1,1),(2,0))'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> isopen(path) </ENTRY> <ENTRY> isopen(path) </ENTRY>
<ENTRY> bool </ENTRY> <ENTRY> bool </ENTRY>
<ENTRY> TRUE if this is an open path </ENTRY> <ENTRY> TRUE if this is an open path </ENTRY>
<ENTRY> isopen('[(0,0),(1,1),(2,0)]'::path) </ENTRY> <ENTRY> isopen('[(0,0),(1,1),(2,0)]'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> length(lseg) </ENTRY> <ENTRY> length(lseg) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> length of line segment </ENTRY> <ENTRY> length of line segment </ENTRY>
<ENTRY> length('((-1,0),(1,0))'::lseg) </ENTRY> <ENTRY> length('((-1,0),(1,0))'::lseg) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> length(path) </ENTRY> <ENTRY> length(path) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> length of path </ENTRY> <ENTRY> length of path </ENTRY>
<ENTRY> length('((0,0),(1,1),(2,0))'::path) </ENTRY> <ENTRY> length('((0,0),(1,1),(2,0))'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> pclose(path) </ENTRY> <ENTRY> pclose(path) </ENTRY>
<ENTRY> path </ENTRY> <ENTRY> path </ENTRY>
<ENTRY> convert path to closed variant </ENTRY> <ENTRY> convert path to closed variant </ENTRY>
<ENTRY> popen('[(0,0),(1,1),(2,0)]'::path) </ENTRY> <ENTRY> popen('[(0,0),(1,1),(2,0)]'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> point(lseg,lseg) </ENTRY> <ENTRY> point(lseg,lseg) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> convert to point (intersection) </ENTRY> <ENTRY> convert to point (intersection) </ENTRY>
<ENTRY> point('((-1,0),(1,0))'::lseg,'((-2,-2),(2,2))'::lseg) </ENTRY> <ENTRY> point('((-1,0),(1,0))'::lseg,'((-2,-2),(2,2))'::lseg) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> points(path) </ENTRY> <ENTRY> points(path) </ENTRY>
<ENTRY> int4 </ENTRY> <ENTRY> int4 </ENTRY>
<ENTRY> number of points in path </ENTRY> <ENTRY> number of points in path </ENTRY>
<ENTRY> points('[(0,0),(1,1),(2,0)]'::path) </ENTRY> <ENTRY> points('[(0,0),(1,1),(2,0)]'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> popen(path) </ENTRY> <ENTRY> popen(path) </ENTRY>
<ENTRY> path </ENTRY> <ENTRY> path </ENTRY>
<ENTRY> convert path to open variant </ENTRY> <ENTRY> convert path to open variant </ENTRY>
<ENTRY> popen('((0,0),(1,1),(2,0))'::path) </ENTRY> <ENTRY> popen('((0,0),(1,1),(2,0))'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> radius(circle) </ENTRY> <ENTRY> radius(circle) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> radius of circle </ENTRY> <ENTRY> radius of circle </ENTRY>
<ENTRY> radius('((0,0),2.0)'::circle) </ENTRY> <ENTRY> radius('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> width(box) </ENTRY> <ENTRY> width(box) </ENTRY>
<ENTRY> float8 </ENTRY> <ENTRY> float8 </ENTRY>
<ENTRY> horizontal size of box </ENTRY> <ENTRY> horizontal size of box </ENTRY>
<ENTRY> width('((0,0),(1,1))'::box) </ENTRY> <ENTRY> width('((0,0),(1,1))'::box) </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>Geometric Type Conversion Functions</TITLE> <TITLE>Geometric Type Conversion Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> box(circle) </ENTRY> <ENTRY> box(circle) </ENTRY>
<ENTRY> box </ENTRY> <ENTRY> box </ENTRY>
<ENTRY> convert circle to box </ENTRY> <ENTRY> convert circle to box </ENTRY>
<ENTRY> box('((0,0),2.0)'::circle) </ENTRY> <ENTRY> box('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> box(point,point) </ENTRY> <ENTRY> box(point,point) </ENTRY>
<ENTRY> box </ENTRY> <ENTRY> box </ENTRY>
<ENTRY> convert points to box </ENTRY> <ENTRY> convert points to box </ENTRY>
<ENTRY> box('(0,0)'::point,'(1,1)'::point) </ENTRY> <ENTRY> box('(0,0)'::point,'(1,1)'::point) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> box(polygon) </ENTRY> <ENTRY> box(polygon) </ENTRY>
<ENTRY> box </ENTRY> <ENTRY> box </ENTRY>
<ENTRY> convert polygon to box </ENTRY> <ENTRY> convert polygon to box </ENTRY>
<ENTRY> box('((0,0),(1,1),(2,0))'::polygon) </ENTRY> <ENTRY> box('((0,0),(1,1),(2,0))'::polygon) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> circle(box) </ENTRY> <ENTRY> circle(box) </ENTRY>
<ENTRY> circle </ENTRY> <ENTRY> circle </ENTRY>
<ENTRY> convert to circle </ENTRY> <ENTRY> convert to circle </ENTRY>
<ENTRY> circle('((0,0),(1,1))'::box) </ENTRY> <ENTRY> circle('((0,0),(1,1))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> circle(point,float8) </ENTRY> <ENTRY> circle(point,float8) </ENTRY>
<ENTRY> circle </ENTRY> <ENTRY> circle </ENTRY>
<ENTRY> convert to circle </ENTRY> <ENTRY> convert to circle </ENTRY>
<ENTRY> circle('(0,0)'::point,2.0) </ENTRY> <ENTRY> circle('(0,0)'::point,2.0) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> lseg(box) </ENTRY> <ENTRY> lseg(box) </ENTRY>
<ENTRY> lseg </ENTRY> <ENTRY> lseg </ENTRY>
<ENTRY> convert diagonal to lseg </ENTRY> <ENTRY> convert diagonal to lseg </ENTRY>
<ENTRY> lseg('((-1,0),(1,0))'::box) </ENTRY> <ENTRY> lseg('((-1,0),(1,0))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> lseg(point,point) </ENTRY> <ENTRY> lseg(point,point) </ENTRY>
<ENTRY> lseg </ENTRY> <ENTRY> lseg </ENTRY>
<ENTRY> convert to lseg </ENTRY> <ENTRY> convert to lseg </ENTRY>
<ENTRY> lseg('(-1,0)'::point,'(1,0)'::point) </ENTRY> <ENTRY> lseg('(-1,0)'::point,'(1,0)'::point) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> path(polygon) </ENTRY> <ENTRY> path(polygon) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> convert to path </ENTRY> <ENTRY> convert to path </ENTRY>
<ENTRY> path('((0,0),(1,1),(2,0))'::polygon) </ENTRY> <ENTRY> path('((0,0),(1,1),(2,0))'::polygon) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> point(circle) </ENTRY> <ENTRY> point(circle) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> convert to point (center) </ENTRY> <ENTRY> convert to point (center) </ENTRY>
<ENTRY> point('((0,0),2.0)'::circle) </ENTRY> <ENTRY> point('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> point(lseg,lseg) </ENTRY> <ENTRY> point(lseg,lseg) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> convert to point (intersection) </ENTRY> <ENTRY> convert to point (intersection) </ENTRY>
<ENTRY> point('((-1,0),(1,0))'::lseg,'((-2,-2),(2,2))'::lseg) </ENTRY> <ENTRY> point('((-1,0),(1,0))'::lseg,'((-2,-2),(2,2))'::lseg) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> point(polygon) </ENTRY> <ENTRY> point(polygon) </ENTRY>
<ENTRY> point </ENTRY> <ENTRY> point </ENTRY>
<ENTRY> center of polygon </ENTRY> <ENTRY> center of polygon </ENTRY>
<ENTRY> point('((0,0),(1,1),(2,0))'::polygon) </ENTRY> <ENTRY> point('((0,0),(1,1),(2,0))'::polygon) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> polygon(box) </ENTRY> <ENTRY> polygon(box) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert to polygon with 12 points </ENTRY> <ENTRY> convert to polygon with 12 points </ENTRY>
<ENTRY> polygon('((0,0),(1,1))'::box) </ENTRY> <ENTRY> polygon('((0,0),(1,1))'::box) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> polygon(circle) </ENTRY> <ENTRY> polygon(circle) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert to polygon with 12 points </ENTRY> <ENTRY> convert to polygon with 12 points </ENTRY>
<ENTRY> polygon('((0,0),2.0)'::circle) </ENTRY> <ENTRY> polygon('((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> polygon(npts,circle) </ENTRY> <ENTRY> polygon(npts,circle) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert to polygon with npts points </ENTRY> <ENTRY> convert to polygon with npts points </ENTRY>
<ENTRY> polygon(12,'((0,0),2.0)'::circle) </ENTRY> <ENTRY> polygon(12,'((0,0),2.0)'::circle) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> polygon(path) </ENTRY> <ENTRY> polygon(path) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert to polygon </ENTRY> <ENTRY> convert to polygon </ENTRY>
<ENTRY> polygon('((0,0),(1,1),(2,0))'::path) </ENTRY> <ENTRY> polygon('((0,0),(1,1),(2,0))'::path) </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE>Geometric Upgrade Functions</TITLE> <TITLE>Geometric Upgrade Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> isoldpath(path) </ENTRY> <ENTRY> isoldpath(path) </ENTRY>
<ENTRY> path </ENTRY> <ENTRY> path </ENTRY>
<ENTRY> test path for pre-v6.1 form </ENTRY> <ENTRY> test path for pre-v6.1 form </ENTRY>
<ENTRY> isoldpath('(1,3,0,0,1,1,2,0)'::path) </ENTRY> <ENTRY> isoldpath('(1,3,0,0,1,1,2,0)'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> revertpoly(polygon) </ENTRY> <ENTRY> revertpoly(polygon) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert pre-v6.1 polygon </ENTRY> <ENTRY> convert pre-v6.1 polygon </ENTRY>
<ENTRY> revertpoly('((0,0),(1,1),(2,0))'::polygon) </ENTRY> <ENTRY> revertpoly('((0,0),(1,1),(2,0))'::polygon) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> upgradepath(path) </ENTRY> <ENTRY> upgradepath(path) </ENTRY>
<ENTRY> path </ENTRY> <ENTRY> path </ENTRY>
<ENTRY> convert pre-v6.1 path </ENTRY> <ENTRY> convert pre-v6.1 path </ENTRY>
<ENTRY> upgradepath('(1,3,0,0,1,1,2,0)'::path) </ENTRY> <ENTRY> upgradepath('(1,3,0,0,1,1,2,0)'::path) </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> upgradepoly(polygon) </ENTRY> <ENTRY> upgradepoly(polygon) </ENTRY>
<ENTRY> polygon </ENTRY> <ENTRY> polygon </ENTRY>
<ENTRY> convert pre-v6.1 polygon </ENTRY> <ENTRY> convert pre-v6.1 polygon </ENTRY>
<ENTRY> upgradepoly('(0,1,2,0,1,0)'::polygon) </ENTRY> <ENTRY> upgradepoly('(0,1,2,0,1,0)'::polygon) </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title id="cidr-funcs">IP V4 Functions</title> <title id="cidr-funcs">IP V4 Functions</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName>IP V4 Functions</TITLE> <TITLE><ProductName>Postgres</ProductName>IP V4 Functions</TITLE>
<TGROUP COLS="4"> <TGROUP COLS="4">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Function</ENTRY> <ENTRY>Function</ENTRY>
<ENTRY>Returns</ENTRY> <ENTRY>Returns</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Example</ENTRY> <ENTRY>Example</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> broadcast(cidr) </ENTRY> <ENTRY> broadcast(cidr) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> construct broadcast address as text </ENTRY> <ENTRY> construct broadcast address as text </ENTRY>
<ENTRY> broadcast('192.168.1.5/24') ==> '192.168.1.255' </ENTRY> <ENTRY> broadcast('192.168.1.5/24') ==> '192.168.1.255' </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> broadcast(inet) </ENTRY> <ENTRY> broadcast(inet) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> construct broadcast address as text </ENTRY> <ENTRY> construct broadcast address as text </ENTRY>
<ENTRY> broadcast('192.168.1.5/24') ==> '192.168.1.255' </ENTRY> <ENTRY> broadcast('192.168.1.5/24') ==> '192.168.1.255' </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> host(inet) </ENTRY> <ENTRY> host(inet) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> extract host address as text </ENTRY> <ENTRY> extract host address as text </ENTRY>
<ENTRY> host('192.168.1.5/24') ==> '192.168.1.5' </ENTRY> <ENTRY> host('192.168.1.5/24') ==> '192.168.1.5' </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> masklen(cidr) </ENTRY> <ENTRY> masklen(cidr) </ENTRY>
<ENTRY> int4 </ENTRY> <ENTRY> int4 </ENTRY>
<ENTRY> calculate netmask length </ENTRY> <ENTRY> calculate netmask length </ENTRY>
<ENTRY> masklen('192.168.1.5/24') ==> 24</ENTRY> <ENTRY> masklen('192.168.1.5/24') ==> 24</ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> masklen(inet) </ENTRY> <ENTRY> masklen(inet) </ENTRY>
<ENTRY> int4 </ENTRY> <ENTRY> int4 </ENTRY>
<ENTRY> calculate netmask length </ENTRY> <ENTRY> calculate netmask length </ENTRY>
<ENTRY> masklen('192.168.1.5/24') ==> 24 </ENTRY> <ENTRY> masklen('192.168.1.5/24') ==> 24 </ENTRY>
</ROW> </ROW>
<ROW> <ROW>
<ENTRY> netmask(inet) </ENTRY> <ENTRY> netmask(inet) </ENTRY>
<ENTRY> text </ENTRY> <ENTRY> text </ENTRY>
<ENTRY> construct netmask as text </ENTRY> <ENTRY> construct netmask as text </ENTRY>
<ENTRY> netmask('192.168.1.5/24') ==> '255.255.255.0' </ENTRY> <ENTRY> netmask('192.168.1.5/24') ==> '255.255.255.0' </ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</Sect1> </Sect1>
</chapter> </chapter>
<!-- Keep this comment at the end of the file <!-- Keep this comment at the end of the file
Local variables: Local variables:
mode: sgml mode: sgml
sgml-omittag:t sgml-omittag:nil
sgml-shorttag:t sgml-shorttag:t
sgml-minimize-attributes:nil sgml-minimize-attributes:nil
sgml-always-quote-attributes:t sgml-always-quote-attributes:t
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doc/src/sgml/oper.sgml
View file @ 95e3cec6
<Chapter Id="operators"> <Chapter Id="operators">
<Title>Operators</Title> <Title id="operators-title">Operators</Title>
<Abstract> <Abstract>
<Para> <Para>
Describes the built-in operators available in Describes the built-in operators available in
<ProductName>Postgres</ProductName>. <ProductName>Postgres</ProductName>.
</Para> </Para>
</Abstract> </Abstract>
<Para> <Para>
<ProductName>Postgres</ProductName> provides a large number of <ProductName>Postgres</ProductName> provides a large number of
built-in operators on system types. built-in operators on system types.
These operators are declared in the system catalog These operators are declared in the system catalog
pg_operator. Every entry in pg_operator includes pg_operator. Every entry in pg_operator includes
the name of the procedure that implements the operator and the the name of the procedure that implements the operator and the
class <Acronym>OIDs</Acronym> of the input and output types. class <Acronym>OIDs</Acronym> of the input and output types.
</Para> </Para>
<Para> <Para>
To view all variations of the <Quote>||</Quote> string concatenation operator, To view all variations of the <Quote>||</Quote> string concatenation operator,
try try
<ProgramListing> <ProgramListing>
SELECT oprleft, oprright, oprresult, oprcode SELECT oprleft, oprright, oprresult, oprcode
FROM pg_operator WHERE oprname = '||'; FROM pg_operator WHERE oprname = '||';
...@@ -30,37 +30,37 @@ oprleft|oprright|oprresult|oprcode ...@@ -30,37 +30,37 @@ oprleft|oprright|oprresult|oprcode
1042| 1042| 1042|textcat 1042| 1042| 1042|textcat
1043| 1043| 1043|textcat 1043| 1043| 1043|textcat
(3 rows) (3 rows)
</ProgramListing> </ProgramListing>
</Para> </Para>
<Para> <Para>
Users may invoke operators using the operator name, as in: Users may invoke operators using the operator name, as in:
<ProgramListing> <ProgramListing>
select * from emp where salary < 40000; select * from emp where salary < 40000;
</ProgramListing> </ProgramListing>
Alternatively, users may call the functions that implement the Alternatively, users may call the functions that implement the
operators directly. In this case, the query above would be expressed operators directly. In this case, the query above would be expressed
as: as:
<ProgramListing> <ProgramListing>
select * from emp where int4lt(salary, 40000); select * from emp where int4lt(salary, 40000);
</ProgramListing> </ProgramListing>
</Para> </Para>
<Para> <Para>
<Application>psql</Application> <Application>psql</Application>
has a command (<Command>\dd</Command>) to show these operators. has a command (<Command>\dd</Command>) to show these operators.
</Para> </Para>
<sect1> <sect1>
<title>Lexical Precedence</title> <title>Lexical Precedence</title>
<para> <para>
Operators have a precedence which is currently hardcoded into the parser. Operators have a precedence which is currently hardcoded into the parser.
Most operators have the same precedence and are left-associative. This may lead 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;" to non-intuitive behavior; for example the boolean operators "&lt;" and "&gt;"
have a different precedence that the boolean operators "&lt;=" and "&gt;=". have a different precedence that the boolean operators "&lt;=" and "&gt;=".
<table tocentry="1"> <table tocentry="1">
<title> <title>
...@@ -322,26 +322,27 @@ logical union ...@@ -322,26 +322,27 @@ logical union
</para> </para>
</sect1> </sect1>
<sect1> <sect1>
<title>General Operators</title> <title>General Operators</title>
<para> <para>
The operators listed here are defined for a number of native data types, The operators listed here are defined for a number of native data types,
ranging from numeric types to data/time types. ranging from numeric types to data/time types.
</para> </para>
<Para>
<TABLE TOCENTRY="1"> <Para>
<TITLE><ProductName>Postgres</ProductName> Operators</TITLE> <TABLE TOCENTRY="1">
<TITLEABBREV>Operators</TITLEABBREV> <TITLE><ProductName>Postgres</ProductName> Operators</TITLE>
<TGROUP COLS="3"> <TITLEABBREV>Operators</TITLEABBREV>
<THEAD> <TGROUP COLS="3">
<THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> &lt; </ENTRY> <ENTRY> &lt; </ENTRY>
<ENTRY>Less than?</ENTRY> <ENTRY>Less than?</ENTRY>
...@@ -412,28 +413,28 @@ ranging from numeric types to data/time types. ...@@ -412,28 +413,28 @@ ranging from numeric types to data/time types.
<ENTRY>Does not match (regex), case insensitive</ENTRY> <ENTRY>Does not match (regex), case insensitive</ENTRY>
<ENTRY>'thomas' !~ '.*vadim.*'</ENTRY> <ENTRY>'thomas' !~ '.*vadim.*'</ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title id="math-opers">Numerical Operators</title> <title id="math-opers">Numerical Operators</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName> Numerical Operators</TITLE> <TITLE><ProductName>Postgres</ProductName> Numerical Operators</TITLE>
<TITLEABBREV>Operators</TITLEABBREV> <TITLEABBREV>Operators</TITLEABBREV>
<TGROUP COLS="3"> <TGROUP COLS="3">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> ! </ENTRY> <ENTRY> ! </ENTRY>
<ENTRY>Factorial</ENTRY> <ENTRY>Factorial</ENTRY>
...@@ -504,28 +505,28 @@ ranging from numeric types to data/time types. ...@@ -504,28 +505,28 @@ ranging from numeric types to data/time types.
<ENTRY>Cube root</ENTRY> <ENTRY>Cube root</ENTRY>
<ENTRY>||/ 27.0</ENTRY> <ENTRY>||/ 27.0</ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title>Geometric Operators</title> <title>Geometric Operators</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName> Geometric Operators</TITLE> <TITLE><ProductName>Postgres</ProductName> Geometric Operators</TITLE>
<TITLEABBREV>Operators</TITLEABBREV> <TITLEABBREV>Operators</TITLEABBREV>
<TGROUP COLS="3"> <TGROUP COLS="3">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> + </ENTRY> <ENTRY> + </ENTRY>
<ENTRY>Translation</ENTRY> <ENTRY>Translation</ENTRY>
...@@ -646,32 +647,32 @@ ranging from numeric types to data/time types. ...@@ -646,32 +647,32 @@ ranging from numeric types to data/time types.
<ENTRY>Same as</ENTRY> <ENTRY>Same as</ENTRY>
<ENTRY>'((0,0),(1,1))'::polygon ~= '((1,1),(0,0))'::polygon</ENTRY> <ENTRY>'((0,0),(1,1))'::polygon ~= '((1,1),(0,0))'::polygon</ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<sect1> <sect1>
<title>Time Interval Operators</title> <title>Time Interval Operators</title>
<Para> <Para>
The time interval data type <Type>tinterval</Type> is a legacy from the original The time interval data type <Type>tinterval</Type> is a legacy from the original
date/time types and is not as well supported as the more modern types. There date/time types and is not as well supported as the more modern types. There
are several operators for this type. are several operators for this type.
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName> Time Interval Operators</TITLE> <TITLE><ProductName>Postgres</ProductName> Time Interval Operators</TITLE>
<TITLEABBREV>Operators</TITLEABBREV> <TITLEABBREV>Operators</TITLEABBREV>
<TGROUP COLS="3"> <TGROUP COLS="3">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> #&lt; </ENTRY> <ENTRY> #&lt; </ENTRY>
<ENTRY>Interval less than?</ENTRY> <ENTRY>Interval less than?</ENTRY>
...@@ -727,28 +728,28 @@ are several operators for this type. ...@@ -727,28 +728,28 @@ are several operators for this type.
<ENTRY>Time inside interval?</ENTRY> <ENTRY>Time inside interval?</ENTRY>
<ENTRY></ENTRY> <ENTRY></ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</sect1> </sect1>
<Sect1> <Sect1>
<title id="cidr-opers">IP V4 CIDR Operators</title> <title id="cidr-opers">IP V4 CIDR Operators</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName>IP V4 CIDR Operators</TITLE> <TITLE><ProductName>Postgres</ProductName>IP V4 CIDR Operators</TITLE>
<TITLEABBREV>Operators</TITLEABBREV> <TITLEABBREV>Operators</TITLEABBREV>
<TGROUP COLS="3"> <TGROUP COLS="3">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> &lt; </ENTRY> <ENTRY> &lt; </ENTRY>
<ENTRY>Less than</ENTRY> <ENTRY>Less than</ENTRY>
...@@ -799,28 +800,28 @@ are several operators for this type. ...@@ -799,28 +800,28 @@ are several operators for this type.
<ENTRY>contains or equals</ENTRY> <ENTRY>contains or equals</ENTRY>
<ENTRY>'192.168.1/24'::cidr &gt;&gt;= '192.168.1/24'::cidr</ENTRY> <ENTRY>'192.168.1/24'::cidr &gt;&gt;= '192.168.1/24'::cidr</ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</Sect1> </Sect1>
<Sect1> <Sect1>
<title id="inet-opers">IP V4 INET Operators</title> <title id="inet-opers">IP V4 INET Operators</title>
<Para> <Para>
<TABLE TOCENTRY="1"> <TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName>IP V4 INET Operators</TITLE> <TITLE><ProductName>Postgres</ProductName>IP V4 INET Operators</TITLE>
<TITLEABBREV>Operators</TITLEABBREV> <TITLEABBREV>Operators</TITLEABBREV>
<TGROUP COLS="3"> <TGROUP COLS="3">
<THEAD> <THEAD>
<ROW> <ROW>
<ENTRY>Operator</ENTRY> <ENTRY>Operator</ENTRY>
<ENTRY>Description</ENTRY> <ENTRY>Description</ENTRY>
<ENTRY>Usage</ENTRY> <ENTRY>Usage</ENTRY>
</ROW> </ROW>
</THEAD> </THEAD>
<TBODY> <TBODY>
<ROW> <ROW>
<ENTRY> &lt; </ENTRY> <ENTRY> &lt; </ENTRY>
<ENTRY>Less than</ENTRY> <ENTRY>Less than</ENTRY>
...@@ -871,11 +872,27 @@ are several operators for this type. ...@@ -871,11 +872,27 @@ are several operators for this type.
<ENTRY>contains or equals</ENTRY> <ENTRY>contains or equals</ENTRY>
<ENTRY>'192.168.1/24'::inet &gt;&gt;= '192.168.1/24'::inet</ENTRY> <ENTRY>'192.168.1/24'::inet &gt;&gt;= '192.168.1/24'::inet</ENTRY>
</ROW> </ROW>
</TBODY> </TBODY>
</TGROUP> </TGROUP>
</TABLE> </TABLE>
</Para> </Para>
</Sect1> </Sect1>
</Chapter> </Chapter>
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mode: sgml
sgml-omittag:nil
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sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"./reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/CATALOG"
sgml-local-ecat-files:nil
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doc/src/sgml/syntax.sgml
View file @ 95e3cec6
<chapter> <chapter>
<title>SQL Syntax</title> <title>SQL Syntax</title>
<sect1> <abstract>
<title>Key Words</title> <para>
<acronym>SQL</acronym> manipulates sets of data. The language is
<para> composed of various <firstterm>key words</firstterm>. Arithmetic
<acronym>SQL92</acronym> defines <firstterm>key words</firstterm> and procedural expressions are allowed. We will cover these topics
for the language in this chapter; subsequent chapters will include details on data
which have specific meaning. Some key words are types, functions, and operators.
<firstterm>reserved</firstterm>, which indicates that they are </para>
restricted to appear in only certain contexts. Other key words are </abstract>
<firstterm>not restricted</firstterm>, which indicates that in certain
contexts they <sect1>
have a specific meaning but are not otherwise constrained. <title>Key Words</title>
</para>
<para>
<para> <acronym>SQL92</acronym> defines <firstterm>key words</firstterm>
<productname>Postgres</productname> implements an extended subset of the for the language
<acronym>SQL92</acronym> and <acronym>SQL3</acronym> languages. Some language which have specific meaning. Some key words are
elements are not as restricted in this implementation as is <firstterm>reserved</firstterm>, which indicates that they are
called for in the language standards, in part due restricted to appear in only certain contexts. Other key words are
to the extensibility features of <productname>Postgres</productname>. <firstterm>not restricted</firstterm>, which indicates that in certain
</para> contexts they
have a specific meaning but are not otherwise constrained.
<para> </para>
Information on <acronym>SQL92</acronym> and <acronym>SQL3</acronym> key words
is derived from <xref linkend="DATE97" endterm="DATE97">. <para>
</para> <productname>Postgres</productname> implements an extended subset of the
<acronym>SQL92</acronym> and <acronym>SQL3</acronym> languages. Some language
<sect2> elements are not as restricted in this implementation as is
<title>Reserved Key Words</title> called for in the language standards, in part due
to the extensibility features of <productname>Postgres</productname>.
<para> </para>
<acronym>SQL92</acronym> and <acronym>SQL3</acronym> have
<firstterm>reserved key words</firstterm> which are not allowed <para>
as identifiers and not allowed in any usage other than as fundamental Information on <acronym>SQL92</acronym> and <acronym>SQL3</acronym> key words
tokens in <acronym>SQL</acronym> statements. is derived from <xref linkend="DATE97" endterm="DATE97">.
<productname>Postgres</productname> has additional key words </para>
which have similar restrictions. In particular, these key words
are not allowed as column or table names, though in some cases <sect2>
they are allowed to be column labels (i.e. in AS clauses). <title>Reserved Key Words</title>
</para>
<para>
<tip> <acronym>SQL92</acronym> and <acronym>SQL3</acronym> have
<para> <firstterm>reserved key words</firstterm> which are not allowed
Any string can be specified as an identifier if surrounded by as identifiers and not allowed in any usage other than as fundamental
double quotes (<quote>like this!</quote>). Some care is required since tokens in <acronym>SQL</acronym> statements.
such an identifier will be case sensitive <productname>Postgres</productname> has additional key words
and will retain embedded whitespace other special characters.</para> which have similar restrictions. In particular, these key words
</tip> are not allowed as column or table names, though in some cases
they are allowed to be column labels (i.e. in AS clauses).
<para> </para>
The following are <productname>Postgres</productname>
reserved words which are neither <acronym>SQL92</acronym> <tip>
nor <acronym>SQL3</acronym> reserved words. These are allowed <para>
to be present as column labels, but not as identifiers: Any string can be specified as an identifier if surrounded by
double quotes (<quote>like this!</quote>). Some care is required since
<programlisting> such an identifier will be case sensitive
and will retain embedded whitespace other special characters.
</para>
</tip>
<para>
The following are <productname>Postgres</productname>
reserved words which are neither <acronym>SQL92</acronym>
nor <acronym>SQL3</acronym> reserved words. These are allowed
to be present as column labels, but not as identifiers:
<programlisting>
ABORT ANALYZE ABORT ANALYZE
BINARY BINARY
CLUSTER CONSTRAINT COPY CLUSTER CONSTRAINT COPY
...@@ -69,32 +80,33 @@ RESET ...@@ -69,32 +80,33 @@ RESET
SETOF SHOW SETOF SHOW
UNLISTEN UNTIL UNLISTEN UNTIL
VACUUM VERBOSE VACUUM VERBOSE
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are <productname>Postgres</productname> The following are <productname>Postgres</productname>
reserved words which are also <acronym>SQL92</acronym> reserved words which are also <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> reserved words, and which or <acronym>SQL3</acronym> reserved words, and which
are allowed to be present as column labels, but not as identifiers: are allowed to be present as column labels, but not as identifiers:
<programlisting> <programlisting>
CASE COALESCE CROSS CURRENT CASE COALESCE CROSS CURRENT
ELSE END ELSE END
FALSE FOREIGN FALSE FOREIGN
GROUP GLOBAL GROUP
LOCAL
NULLIF NULLIF
ORDER ORDER
POSITION PRECISION POSITION PRECISION
TABLE THEN TRANSACTION TRUE TABLE THEN TRANSACTION TRUE
WHEN WHEN
</programlisting> </programlisting>
The following are <productname>Postgres</productname> The following are <productname>Postgres</productname>
reserved words which are also <acronym>SQL92</acronym> reserved words which are also <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> reserved words: or <acronym>SQL3</acronym> reserved words:
<programlisting> <programlisting>
ADD ALL ALTER AND ANY AS ASC ADD ALL ALTER AND ANY AS ASC
BEGIN BETWEEN BOTH BY BEGIN BETWEEN BOTH BY
CASCADE CAST CHAR CHARACTER CHECK CLOSE CASCADE CAST CHAR CHARACTER CHECK CLOSE
...@@ -118,49 +130,49 @@ TO TRAILING TRIM ...@@ -118,49 +130,49 @@ TO TRAILING TRIM
UNION UNIQUE UPDATE USER USING UNION UNIQUE UPDATE USER USING
VALUES VARCHAR VARYING VIEW VALUES VARCHAR VARYING VIEW
WHERE WITH WORK WHERE WITH WORK
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are <acronym>SQL92</acronym> reserved key words which The following are <acronym>SQL92</acronym> reserved key words which
are not <productname>Postgres</productname> reserved key words, but which are not <productname>Postgres</productname> reserved key words, but which
if used as function names are always translated into the function if used as function names are always translated into the function
<function>length</function>: <function>length</function>:
<programlisting> <programlisting>
CHAR_LENGTH CHARACTER_LENGTH CHAR_LENGTH CHARACTER_LENGTH
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are <acronym>SQL92</acronym> or <acronym>SQL3</acronym> The following are <acronym>SQL92</acronym> or <acronym>SQL3</acronym>
reserved key words which reserved key words which
are not <productname>Postgres</productname> reserved key words, but are not <productname>Postgres</productname> reserved key words, but
if used as type names are always translated into an alternate, native type: if used as type names are always translated into an alternate, native type:
<programlisting> <programlisting>
BOOLEAN DOUBLE FLOAT INT INTEGER INTERVAL REAL SMALLINT BOOLEAN DOUBLE FLOAT INT INTEGER INTERVAL REAL SMALLINT
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are either <acronym>SQL92</acronym> The following are either <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> reserved key words or <acronym>SQL3</acronym> reserved key words
which are not key words in <productname>Postgres</productname>. which are not key words in <productname>Postgres</productname>.
These have no proscribed usage in <productname>Postgres</productname> These have no proscribed usage in <productname>Postgres</productname>
at the time of writing (v6.4) but may become reserved key words in the at the time of writing (v6.5) but may become reserved key words in the
future: future:
<note> <note>
<para> <para>
Some of these key words represent functions in <acronym>SQL92</acronym>. Some of these key words represent functions in <acronym>SQL92</acronym>.
These functions are defined in <productname>Postgres</productname>, These functions are defined in <productname>Postgres</productname>,
but the parser does not consider the names to be key words and they are allowed but the parser does not consider the names to be key words and they are allowed
in other contexts. in other contexts.
</para> </para>
</note> </note>
<programlisting> <programlisting>
ALLOCATE ARE ASSERTION AT AUTHORIZATION AVG ALLOCATE ARE ASSERTION AT AUTHORIZATION AVG
BIT BIT_LENGTH BIT BIT_LENGTH
CASCADED CATALOG COLLATION CONNECT CONNECTION CASCADED CATALOG COLLATION CONNECT CONNECTION
...@@ -168,7 +180,7 @@ CASCADED CATALOG COLLATION CONNECT CONNECTION ...@@ -168,7 +180,7 @@ CASCADED CATALOG COLLATION CONNECT CONNECTION
DATE DEALLOCATE DEC DESCRIBE DESCRIPTOR DIAGNOSTICS DISCONNECT DOMAIN DATE DEALLOCATE DEC DESCRIBE DESCRIPTOR DIAGNOSTICS DISCONNECT DOMAIN
END-EXEC ESCAPE EXCEPT EXCEPTION EXEC EXTERNAL END-EXEC ESCAPE EXCEPT EXCEPTION EXEC EXTERNAL
FIRST FOUND FIRST FOUND
GET GLOBAL GO GOTO GET GO GOTO
IDENTITY IMMEDIATE INDICATOR INITIALLY INPUT INTERSECT ISOLATION IDENTITY IMMEDIATE INDICATOR INITIALLY INPUT INTERSECT ISOLATION
LAST LEVEL LOWER LAST LEVEL LOWER
MAX MIN MODULE MAX MIN MODULE
...@@ -181,56 +193,56 @@ TEMPORARY TRANSLATE TRANSLATION ...@@ -181,56 +193,56 @@ TEMPORARY TRANSLATE TRANSLATION
UNKNOWN UPPER USAGE UNKNOWN UPPER USAGE
VALUE VALUE
WHENEVER WRITE WHENEVER WRITE
</programlisting> </programlisting>
</para> </para>
</sect2> </sect2>
<sect2> <sect2>
<title>Non-reserved Keywords</title> <title>Non-reserved Keywords</title>
<para> <para>
<acronym>SQL92</acronym> and <acronym>SQL3</acronym> have <acronym>SQL92</acronym> and <acronym>SQL3</acronym> have
<firstterm>non-reserved keywords</firstterm> which have <firstterm>non-reserved keywords</firstterm> which have
a proscribed meaning in the language but which are also allowed a proscribed meaning in the language but which are also allowed
as identifiers. as identifiers.
<productname>Postgres</productname> has additional keywords <productname>Postgres</productname> has additional keywords
which allow similar unrestricted usage. which allow similar unrestricted usage.
In particular, these keywords In particular, these keywords
are allowed as column or table names. are allowed as column or table names.
</para> </para>
<para> <para>
The following are <productname>Postgres</productname> The following are <productname>Postgres</productname>
non-reserved key words which are neither <acronym>SQL92</acronym> non-reserved key words which are neither <acronym>SQL92</acronym>
nor <acronym>SQL3</acronym> non-reserved key words: nor <acronym>SQL3</acronym> non-reserved key words:
<programlisting> <programlisting>
AFTER AGGREGATE ACCESS AFTER AGGREGATE
BACKWARD BEFORE BACKWARD BEFORE
CACHE CREATEDB CREATEUSER CYCLE CACHE CREATEDB CREATEUSER CYCLE
DATABASE DELIMITERS DATABASE DELIMITERS
EACH ENCODING EACH ENCODING EXCLUSIVE
FORWARD FUNCTION FORWARD FUNCTION
HANDLER HANDLER
INCREMENT INDEX INHERITS INSENSITIVE INSTEAD ISNULL INCREMENT INDEX INHERITS INSENSITIVE INSTEAD ISNULL
LANCOMPILER LOCATION LANCOMPILER LOCATION
MAXVALUE MINVALUE MAXVALUE MINVALUE MODE
NOCREATEDB NOCREATEUSER NOTHING NOTNULL NOCREATEDB NOCREATEUSER NOTHING NOTNULL
OIDS OPERATOR OIDS OPERATOR
PASSWORD PROCEDURAL PASSWORD PROCEDURAL
RECIPE RENAME RETURNS ROW RULE RECIPE RENAME RETURNS ROW RULE
SEQUENCE SERIAL START STATEMENT STDIN STDOUT SEQUENCE SERIAL SHARE START STATEMENT STDIN STDOUT
TRUSTED TRUSTED
VALID VERSION VALID VERSION
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are <productname>Postgres</productname> The following are <productname>Postgres</productname>
non-reserved key words which are <acronym>SQL92</acronym> non-reserved key words which are <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> reserved key words: or <acronym>SQL3</acronym> reserved key words:
<programlisting> <programlisting>
ABSOLUTE ACTION ABSOLUTE ACTION
DAY DAY
HOUR HOUR
...@@ -246,30 +258,30 @@ SCROLL SECOND ...@@ -246,30 +258,30 @@ SCROLL SECOND
TIME TIMESTAMP TIMEZONE_HOUR TIMEZONE_MINUTE TRIGGER TIME TIMESTAMP TIMEZONE_HOUR TIMEZONE_MINUTE TRIGGER
YEAR YEAR
ZONE ZONE
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are <productname>Postgres</productname> The following are <productname>Postgres</productname>
non-reserved key words which are also either <acronym>SQL92</acronym> non-reserved key words which are also either <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> non-reserved key words: or <acronym>SQL3</acronym> non-reserved key words:
<programlisting> <programlisting>
TYPE COMMITTED SERIALIZABLE TYPE
</programlisting> </programlisting>
</para> </para>
<para> <para>
The following are either <acronym>SQL92</acronym> The following are either <acronym>SQL92</acronym>
or <acronym>SQL3</acronym> non-reserved key words which are not or <acronym>SQL3</acronym> non-reserved key words which are not
key words of any kind in <productname>Postgres</productname>: key words of any kind in <productname>Postgres</productname>:
<programlisting> <programlisting>
ADA ADA
C CATALOG_NAME CHARACTER_SET_CATALOG CHARACTER_SET_NAME C CATALOG_NAME CHARACTER_SET_CATALOG CHARACTER_SET_NAME
CHARACTER_SET_SCHEMA CLASS_ORIGIN COBOL COLLATION_CATALOG CHARACTER_SET_SCHEMA CLASS_ORIGIN COBOL COLLATION_CATALOG
COLLATION_NAME COLLATION_SCHEMA COLUMN_NAME COLLATION_NAME COLLATION_SCHEMA COLUMN_NAME
COMMAND_FUNCTION COMMITTED CONDITION_NUMBER COMMAND_FUNCTION CONDITION_NUMBER
CONNECTION_NAME CONSTRAINT_CATALOG CONSTRAINT_NAME CONNECTION_NAME CONSTRAINT_CATALOG CONSTRAINT_NAME
CONSTRAINT_SCHEMA CURSOR_NAME CONSTRAINT_SCHEMA CURSOR_NAME
DATA DATE_TIME_INTERVAL_CODE DATE_TIME_INTERVAL_PRECISION DATA DATE_TIME_INTERVAL_CODE DATE_TIME_INTERVAL_PRECISION
...@@ -281,15 +293,29 @@ NAME NULLABLE NUMBER ...@@ -281,15 +293,29 @@ NAME NULLABLE NUMBER
PAD PASCAL PLI PAD PASCAL PLI
REPEATABLE RETURNED_LENGTH RETURNED_OCTET_LENGTH REPEATABLE RETURNED_LENGTH RETURNED_OCTET_LENGTH
RETURNED_SQLSTATE ROW_COUNT RETURNED_SQLSTATE ROW_COUNT
SCALE SCHEMA_NAME SERIALIZABLE SERVER_NAME SPACE SCALE SCHEMA_NAME SERVER_NAME SPACE
SUBCLASS_ORIGIN SUBCLASS_ORIGIN
TABLE_NAME TABLE_NAME
UNCOMMITTED UNNAMED UNCOMMITTED UNNAMED
</programlisting> </programlisting>
</para> </para>
</sect2> </sect2>
</sect1> </sect1>
</chapter>
<sect1>
<title>Expressions</title>
<para>
<acronym>SQL92</acronym> allows <firstterm>expressions</firstterm>
to transform data in expressions. Expressions may contain operators
(see <xref linkend="operators-title" endterm="operators-title">
for more details) and functions
(<xref linkend="functions-title" endterm="functions-title"> has
more information).
</para>
</sect1>
</chapter>
<!-- Keep this comment at the end of the file <!-- Keep this comment at the end of the file
Local variables: Local variables:
......
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