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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="MULTIBYTE"
>22.3. Character Set Support</A
></H1
><P
> The character set support in <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
allows you to store text in a variety of character sets (also called
encodings), including
single-byte character sets such as the ISO 8859 series and
multiple-byte character sets such as <ACRONYM
CLASS="ACRONYM"
>EUC</ACRONYM
> (Extended Unix
Code), UTF-8, and Mule internal code. All supported character sets
can be used transparently by clients, but a few are not supported
for use within the server (that is, as a server-side encoding).
The default character set is selected while
initializing your <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> database
cluster using <TT
CLASS="COMMAND"
>initdb</TT
>. It can be overridden when you
create a database, so you can have multiple
databases each with a different character set.
</P
><P
> An important restriction, however, is that each database's character set
must be compatible with the database's <TT
CLASS="ENVAR"
>LC_CTYPE</TT
> (character
classification) and <TT
CLASS="ENVAR"
>LC_COLLATE</TT
> (string sort order) locale
settings. For <TT
CLASS="LITERAL"
>C</TT
> or
<TT
CLASS="LITERAL"
>POSIX</TT
> locale, any character set is allowed, but for other
locales there is only one character set that will work correctly.
(On Windows, however, UTF-8 encoding can be used with any locale.)
</P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="MULTIBYTE-CHARSET-SUPPORTED"
>22.3.1. Supported Character Sets</A
></H2
><P
> <A
HREF="multibyte.html#CHARSET-TABLE"
>Table 22-1</A
> shows the character sets available
for use in <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>.
</P
><DIV
CLASS="TABLE"
><A
NAME="CHARSET-TABLE"
></A
><P
><B
>Table 22-1. <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> Character Sets</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><COL><COL><THEAD
><TR
><TH
>Name</TH
><TH
>Description</TH
><TH
>Language</TH
><TH
>Server?</TH
><TH
>Bytes/Char</TH
><TH
>Aliases</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>BIG5</TT
></TD
><TD
>Big Five</TD
><TD
>Traditional Chinese</TD
><TD
>No</TD
><TD
>1-2</TD
><TD
><TT
CLASS="LITERAL"
>WIN950</TT
>, <TT
CLASS="LITERAL"
>Windows950</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_CN</TT
></TD
><TD
>Extended UNIX Code-CN</TD
><TD
>Simplified Chinese</TD
><TD
>Yes</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_JP</TT
></TD
><TD
>Extended UNIX Code-JP</TD
><TD
>Japanese</TD
><TD
>Yes</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_JIS_2004</TT
></TD
><TD
>Extended UNIX Code-JP, JIS X 0213</TD
><TD
>Japanese</TD
><TD
>Yes</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_KR</TT
></TD
><TD
>Extended UNIX Code-KR</TD
><TD
>Korean</TD
><TD
>Yes</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_TW</TT
></TD
><TD
>Extended UNIX Code-TW</TD
><TD
>Traditional Chinese, Taiwanese</TD
><TD
>Yes</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>GB18030</TT
></TD
><TD
>National Standard</TD
><TD
>Chinese</TD
><TD
>No</TD
><TD
>1-4</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>GBK</TT
></TD
><TD
>Extended National Standard</TD
><TD
>Simplified Chinese</TD
><TD
>No</TD
><TD
>1-2</TD
><TD
><TT
CLASS="LITERAL"
>WIN936</TT
>, <TT
CLASS="LITERAL"
>Windows936</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_5</TT
></TD
><TD
>ISO 8859-5, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 113</TD
><TD
>Latin/Cyrillic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_6</TT
></TD
><TD
>ISO 8859-6, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 114</TD
><TD
>Latin/Arabic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_7</TT
></TD
><TD
>ISO 8859-7, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 118</TD
><TD
>Latin/Greek</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_8</TT
></TD
><TD
>ISO 8859-8, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 121</TD
><TD
>Latin/Hebrew</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>JOHAB</TT
></TD
><TD
><ACRONYM
CLASS="ACRONYM"
>JOHAB</ACRONYM
></TD
><TD
>Korean (Hangul)</TD
><TD
>No</TD
><TD
>1-3</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>KOI8R</TT
></TD
><TD
><ACRONYM
CLASS="ACRONYM"
>KOI</ACRONYM
>8-R</TD
><TD
>Cyrillic (Russian)</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>KOI8</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>KOI8U</TT
></TD
><TD
><ACRONYM
CLASS="ACRONYM"
>KOI</ACRONYM
>8-U</TD
><TD
>Cyrillic (Ukrainian)</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN1</TT
></TD
><TD
>ISO 8859-1, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 94</TD
><TD
>Western European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO88591</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN2</TT
></TD
><TD
>ISO 8859-2, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 94</TD
><TD
>Central European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO88592</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN3</TT
></TD
><TD
>ISO 8859-3, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 94</TD
><TD
>South European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO88593</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN4</TT
></TD
><TD
>ISO 8859-4, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 94</TD
><TD
>North European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO88594</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN5</TT
></TD
><TD
>ISO 8859-9, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 128</TD
><TD
>Turkish</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO88599</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN6</TT
></TD
><TD
>ISO 8859-10, <ACRONYM
CLASS="ACRONYM"
>ECMA</ACRONYM
> 144</TD
><TD
>Nordic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO885910</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN7</TT
></TD
><TD
>ISO 8859-13</TD
><TD
>Baltic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO885913</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN8</TT
></TD
><TD
>ISO 8859-14</TD
><TD
>Celtic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO885914</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN9</TT
></TD
><TD
>ISO 8859-15</TD
><TD
>LATIN1 with Euro and accents</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO885915</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN10</TT
></TD
><TD
>ISO 8859-16, <ACRONYM
CLASS="ACRONYM"
>ASRO</ACRONYM
> SR 14111</TD
><TD
>Romanian</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ISO885916</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
></TD
><TD
>Mule internal code</TD
><TD
>Multilingual Emacs</TD
><TD
>Yes</TD
><TD
>1-4</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SJIS</TT
></TD
><TD
>Shift JIS</TD
><TD
>Japanese</TD
><TD
>No</TD
><TD
>1-2</TD
><TD
><TT
CLASS="LITERAL"
>Mskanji</TT
>, <TT
CLASS="LITERAL"
>ShiftJIS</TT
>, <TT
CLASS="LITERAL"
>WIN932</TT
>, <TT
CLASS="LITERAL"
>Windows932</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SHIFT_JIS_2004</TT
></TD
><TD
>Shift JIS, JIS X 0213</TD
><TD
>Japanese</TD
><TD
>No</TD
><TD
>1-2</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SQL_ASCII</TT
></TD
><TD
>unspecified (see text)</TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>any</I
></SPAN
></TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>UHC</TT
></TD
><TD
>Unified Hangul Code</TD
><TD
>Korean</TD
><TD
>No</TD
><TD
>1-2</TD
><TD
><TT
CLASS="LITERAL"
>WIN949</TT
>, <TT
CLASS="LITERAL"
>Windows949</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>UTF8</TT
></TD
><TD
>Unicode, 8-bit</TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>all</I
></SPAN
></TD
><TD
>Yes</TD
><TD
>1-4</TD
><TD
><TT
CLASS="LITERAL"
>Unicode</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN866</TT
></TD
><TD
>Windows CP866</TD
><TD
>Cyrillic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ALT</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN874</TT
></TD
><TD
>Windows CP874</TD
><TD
>Thai</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1250</TT
></TD
><TD
>Windows CP1250</TD
><TD
>Central European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1251</TT
></TD
><TD
>Windows CP1251</TD
><TD
>Cyrillic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>WIN</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1252</TT
></TD
><TD
>Windows CP1252</TD
><TD
>Western European</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1253</TT
></TD
><TD
>Windows CP1253</TD
><TD
>Greek</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1254</TT
></TD
><TD
>Windows CP1254</TD
><TD
>Turkish</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1255</TT
></TD
><TD
>Windows CP1255</TD
><TD
>Hebrew</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1256</TT
></TD
><TD
>Windows CP1256</TD
><TD
>Arabic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1257</TT
></TD
><TD
>Windows CP1257</TD
><TD
>Baltic</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
> </TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1258</TT
></TD
><TD
>Windows CP1258</TD
><TD
>Vietnamese</TD
><TD
>Yes</TD
><TD
>1</TD
><TD
><TT
CLASS="LITERAL"
>ABC</TT
>, <TT
CLASS="LITERAL"
>TCVN</TT
>, <TT
CLASS="LITERAL"
>TCVN5712</TT
>, <TT
CLASS="LITERAL"
>VSCII</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><P
> Not all client <ACRONYM
CLASS="ACRONYM"
>API</ACRONYM
>s support all the listed character sets. For example, the
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
JDBC driver does not support <TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>, <TT
CLASS="LITERAL"
>LATIN6</TT
>,
<TT
CLASS="LITERAL"
>LATIN8</TT
>, and <TT
CLASS="LITERAL"
>LATIN10</TT
>.
</P
><P
> The <TT
CLASS="LITERAL"
>SQL_ASCII</TT
> setting behaves considerably differently
from the other settings. When the server character set is
<TT
CLASS="LITERAL"
>SQL_ASCII</TT
>, the server interprets byte values 0-127
according to the ASCII standard, while byte values 128-255 are taken
as uninterpreted characters. No encoding conversion will be done when
the setting is <TT
CLASS="LITERAL"
>SQL_ASCII</TT
>. Thus, this setting is not so
much a declaration that a specific encoding is in use, as a declaration
of ignorance about the encoding. In most cases, if you are
working with any non-ASCII data, it is unwise to use the
<TT
CLASS="LITERAL"
>SQL_ASCII</TT
> setting because
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> will be unable to help you by
converting or validating non-ASCII characters.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN33549"
>22.3.2. Setting the Character Set</A
></H2
><P
> <TT
CLASS="COMMAND"
>initdb</TT
> defines the default character set (encoding)
for a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> cluster. For example,
</P><PRE
CLASS="SCREEN"
>initdb -E EUC_JP</PRE
><P>
sets the default character set to
<TT
CLASS="LITERAL"
>EUC_JP</TT
> (Extended Unix Code for Japanese). You
can use <TT
CLASS="OPTION"
>--encoding</TT
> instead of
<TT
CLASS="OPTION"
>-E</TT
> if you prefer longer option strings.
If no <TT
CLASS="OPTION"
>-E</TT
> or <TT
CLASS="OPTION"
>--encoding</TT
> option is
given, <TT
CLASS="COMMAND"
>initdb</TT
> attempts to determine the appropriate
encoding to use based on the specified or default locale.
</P
><P
> You can specify a non-default encoding at database creation time,
provided that the encoding is compatible with the selected locale:
</P><PRE
CLASS="SCREEN"
>createdb -E EUC_KR -T template0 --lc-collate=ko_KR.euckr --lc-ctype=ko_KR.euckr korean</PRE
><P>
This will create a database named <TT
CLASS="LITERAL"
>korean</TT
> that
uses the character set <TT
CLASS="LITERAL"
>EUC_KR</TT
>, and locale <TT
CLASS="LITERAL"
>ko_KR</TT
>.
Another way to accomplish this is to use this SQL command:
</P><PRE
CLASS="PROGRAMLISTING"
>CREATE DATABASE korean WITH ENCODING 'EUC_KR' LC_COLLATE='ko_KR.euckr' LC_CTYPE='ko_KR.euckr' TEMPLATE=template0;</PRE
><P>
Notice that the above commands specify copying the <TT
CLASS="LITERAL"
>template0</TT
>
database. When copying any other database, the encoding and locale
settings cannot be changed from those of the source database, because
that might result in corrupt data. For more information see
<A
HREF="manage-ag-templatedbs.html"
>Section 21.3</A
>.
</P
><P
> The encoding for a database is stored in the system catalog
<TT
CLASS="LITERAL"
>pg_database</TT
>. You can see it by using the
<TT
CLASS="COMMAND"
>psql</TT
> <TT
CLASS="OPTION"
>-l</TT
> option or the
<TT
CLASS="COMMAND"
>\l</TT
> command.
</P><PRE
CLASS="SCREEN"
>$ <KBD
CLASS="USERINPUT"
>psql -l</KBD
>
List of databases
Name | Owner | Encoding | Collation | Ctype | Access Privileges
-----------+----------+-----------+-------------+-------------+-------------------------------------
clocaledb | hlinnaka | SQL_ASCII | C | C |
englishdb | hlinnaka | UTF8 | en_GB.UTF8 | en_GB.UTF8 |
japanese | hlinnaka | UTF8 | ja_JP.UTF8 | ja_JP.UTF8 |
korean | hlinnaka | EUC_KR | ko_KR.euckr | ko_KR.euckr |
postgres | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 |
template0 | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 | {=c/hlinnaka,hlinnaka=CTc/hlinnaka}
template1 | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 | {=c/hlinnaka,hlinnaka=CTc/hlinnaka}
(7 rows)</PRE
><P>
</P
><DIV
CLASS="IMPORTANT"
><BLOCKQUOTE
CLASS="IMPORTANT"
><P
><B
>Important: </B
> On most modern operating systems, <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
can determine which character set is implied by the <TT
CLASS="ENVAR"
>LC_CTYPE</TT
>
setting, and it will enforce that only the matching database encoding is
used. On older systems it is your responsibility to ensure that you use
the encoding expected by the locale you have selected. A mistake in
this area is likely to lead to strange behavior of locale-dependent
operations such as sorting.
</P
><P
> <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> will allow superusers to create
databases with <TT
CLASS="LITERAL"
>SQL_ASCII</TT
> encoding even when
<TT
CLASS="ENVAR"
>LC_CTYPE</TT
> is not <TT
CLASS="LITERAL"
>C</TT
> or <TT
CLASS="LITERAL"
>POSIX</TT
>. As noted
above, <TT
CLASS="LITERAL"
>SQL_ASCII</TT
> does not enforce that the data stored in
the database has any particular encoding, and so this choice poses risks
of locale-dependent misbehavior. Using this combination of settings is
deprecated and may someday be forbidden altogether.
</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN33587"
>22.3.3. Automatic Character Set Conversion Between Server and Client</A
></H2
><P
> <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> supports automatic
character set conversion between server and client for certain
character set combinations. The conversion information is stored in the
<TT
CLASS="LITERAL"
>pg_conversion</TT
> system catalog. <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
comes with some predefined conversions, as shown in <A
HREF="multibyte.html#MULTIBYTE-TRANSLATION-TABLE"
>Table 22-2</A
>. You can create a new
conversion using the SQL command <TT
CLASS="COMMAND"
>CREATE CONVERSION</TT
>.
</P
><DIV
CLASS="TABLE"
><A
NAME="MULTIBYTE-TRANSLATION-TABLE"
></A
><P
><B
>Table 22-2. Client/Server Character Set Conversions</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Server Character Set</TH
><TH
>Available Client Character Sets</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>BIG5</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not supported as a server encoding</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_CN</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>EUC_CN</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_JP</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>EUC_JP</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>SJIS</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_KR</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>EUC_KR</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EUC_TW</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>EUC_TW</I
></SPAN
>,
<TT
CLASS="LITERAL"
>BIG5</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>GB18030</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not supported as a server encoding</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>GBK</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not supported as a server encoding</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_5</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ISO_8859_5</I
></SPAN
>,
<TT
CLASS="LITERAL"
>KOI8R</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>,
<TT
CLASS="LITERAL"
>WIN866</TT
>,
<TT
CLASS="LITERAL"
>WIN1251</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_6</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ISO_8859_6</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_7</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ISO_8859_7</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ISO_8859_8</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ISO_8859_8</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>JOHAB</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>JOHAB</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>KOI8R</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>KOI8R</I
></SPAN
>,
<TT
CLASS="LITERAL"
>ISO_8859_5</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>,
<TT
CLASS="LITERAL"
>WIN866</TT
>,
<TT
CLASS="LITERAL"
>WIN1251</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>KOI8U</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>KOI8U</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN1</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN1</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN2</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN2</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>,
<TT
CLASS="LITERAL"
>WIN1250</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN3</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN3</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN4</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN4</I
></SPAN
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN5</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN5</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN6</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN6</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN7</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN7</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN8</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN8</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN9</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN9</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>LATIN10</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>LATIN10</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>MULE_INTERNAL</I
></SPAN
>,
<TT
CLASS="LITERAL"
>BIG5</TT
>,
<TT
CLASS="LITERAL"
>EUC_CN</TT
>,
<TT
CLASS="LITERAL"
>EUC_JP</TT
>,
<TT
CLASS="LITERAL"
>EUC_KR</TT
>,
<TT
CLASS="LITERAL"
>EUC_TW</TT
>,
<TT
CLASS="LITERAL"
>ISO_8859_5</TT
>,
<TT
CLASS="LITERAL"
>KOI8R</TT
>,
<TT
CLASS="LITERAL"
>LATIN1</TT
> to <TT
CLASS="LITERAL"
>LATIN4</TT
>,
<TT
CLASS="LITERAL"
>SJIS</TT
>,
<TT
CLASS="LITERAL"
>WIN866</TT
>,
<TT
CLASS="LITERAL"
>WIN1250</TT
>,
<TT
CLASS="LITERAL"
>WIN1251</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SJIS</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not supported as a server encoding</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SQL_ASCII</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>any (no conversion will be performed)</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>UHC</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not supported as a server encoding</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>UTF8</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>all supported encodings</I
></SPAN
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN866</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN866</I
></SPAN
>,
<TT
CLASS="LITERAL"
>ISO_8859_5</TT
>,
<TT
CLASS="LITERAL"
>KOI8R</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>,
<TT
CLASS="LITERAL"
>WIN1251</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN874</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN874</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1250</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1250</I
></SPAN
>,
<TT
CLASS="LITERAL"
>LATIN2</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1251</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1251</I
></SPAN
>,
<TT
CLASS="LITERAL"
>ISO_8859_5</TT
>,
<TT
CLASS="LITERAL"
>KOI8R</TT
>,
<TT
CLASS="LITERAL"
>MULE_INTERNAL</TT
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>,
<TT
CLASS="LITERAL"
>WIN866</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1252</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1252</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1253</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1253</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1254</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1254</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1255</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1255</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1256</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1256</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1257</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1257</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WIN1258</TT
></TD
><TD
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>WIN1258</I
></SPAN
>,
<TT
CLASS="LITERAL"
>UTF8</TT
>
</TD
></TR
></TBODY
></TABLE
></DIV
><P
> To enable automatic character set conversion, you have to
tell <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> the character set
(encoding) you would like to use in the client. There are several
ways to accomplish this:
<P
></P
></P><UL
><LI
><P
> Using the <TT
CLASS="COMMAND"
>\encoding</TT
> command in
<SPAN
CLASS="APPLICATION"
>psql</SPAN
>.
<TT
CLASS="COMMAND"
>\encoding</TT
> allows you to change client
encoding on the fly. For
example, to change the encoding to <TT
CLASS="LITERAL"
>SJIS</TT
>, type:
</P><PRE
CLASS="PROGRAMLISTING"
>\encoding SJIS</PRE
><P>
</P
></LI
><LI
><P
> <SPAN
CLASS="APPLICATION"
>libpq</SPAN
> (<A
HREF="libpq-control.html"
>Section 31.10</A
>) has functions to control the client encoding.
</P
></LI
><LI
><P
> Using <TT
CLASS="COMMAND"
>SET client_encoding TO</TT
>.
Setting the client encoding can be done with this SQL command:
</P><PRE
CLASS="PROGRAMLISTING"
>SET CLIENT_ENCODING TO '<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>';</PRE
><P>
Also you can use the standard SQL syntax <TT
CLASS="LITERAL"
>SET NAMES</TT
>
for this purpose:
</P><PRE
CLASS="PROGRAMLISTING"
>SET NAMES '<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>';</PRE
><P>
To query the current client encoding:
</P><PRE
CLASS="PROGRAMLISTING"
>SHOW client_encoding;</PRE
><P>
To return to the default encoding:
</P><PRE
CLASS="PROGRAMLISTING"
>RESET client_encoding;</PRE
><P>
</P
></LI
><LI
><P
> Using <TT
CLASS="ENVAR"
>PGCLIENTENCODING</TT
>. If the environment variable
<TT
CLASS="ENVAR"
>PGCLIENTENCODING</TT
> is defined in the client's
environment, that client encoding is automatically selected
when a connection to the server is made. (This can
subsequently be overridden using any of the other methods
mentioned above.)
</P
></LI
><LI
><P
> Using the configuration variable <A
HREF="runtime-config-client.html#GUC-CLIENT-ENCODING"
>client_encoding</A
>. If the
<TT
CLASS="VARNAME"
>client_encoding</TT
> variable is set, that client
encoding is automatically selected when a connection to the
server is made. (This can subsequently be overridden using any
of the other methods mentioned above.)
</P
></LI
></UL
><P>
</P
><P
> If the conversion of a particular character is not possible
— suppose you chose <TT
CLASS="LITERAL"
>EUC_JP</TT
> for the
server and <TT
CLASS="LITERAL"
>LATIN1</TT
> for the client, and some
Japanese characters are returned that do not have a representation in
<TT
CLASS="LITERAL"
>LATIN1</TT
> — an error is reported.
</P
><P
> If the client character set is defined as <TT
CLASS="LITERAL"
>SQL_ASCII</TT
>,
encoding conversion is disabled, regardless of the server's character
set. Just as for the server, use of <TT
CLASS="LITERAL"
>SQL_ASCII</TT
> is unwise
unless you are working with all-ASCII data.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN33916"
>22.3.4. Further Reading</A
></H2
><P
> These are good sources to start learning about various kinds of encoding
systems.
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><I
CLASS="CITETITLE"
>CJKV Information Processing: Chinese, Japanese, Korean & Vietnamese Computing</I
></DT
><DD
><P
> Contains detailed explanations of <TT
CLASS="LITERAL"
>EUC_JP</TT
>,
<TT
CLASS="LITERAL"
>EUC_CN</TT
>, <TT
CLASS="LITERAL"
>EUC_KR</TT
>,
<TT
CLASS="LITERAL"
>EUC_TW</TT
>.
</P
></DD
><DT
><A
HREF="http://www.unicode.org/"
TARGET="_top"
>http://www.unicode.org/</A
></DT
><DD
><P
> The web site of the Unicode Consortium.
</P
></DD
><DT
>RFC 3629</DT
><DD
><P
> <ACRONYM
CLASS="ACRONYM"
>UTF</ACRONYM
>-8 (8-bit UCS/Unicode Transformation
Format) is defined here.
</P
></DD
></DL
></DIV
><P>
</P
></DIV
></DIV
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