Add mention of bytea data type and escaping rules.

This commit is contained in:
Bruce Momjian 2001-09-04 03:17:54 +00:00
parent b553cba15a
commit 9b77572662
1 changed files with 25 additions and 2 deletions

View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.60 2001/08/31 01:55:25 ishii Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.61 2001/09/04 03:17:54 momjian Exp $
-->
<chapter id="datatype">
@ -83,6 +83,12 @@ $Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.60 2001/08/31 01:55:25 is
<entry>rectangular box in 2D plane</entry>
</row>
<row>
<entry><type>bytea</type></entry>
<entry></entry>
<entry>binary data</entry>
</row>
<row>
<entry><type>character(<replaceable>n</replaceable>)</type></entry>
<entry><type>char(<replaceable>n</replaceable>)</type></entry>
@ -782,7 +788,11 @@ CREATE TABLE <replaceable class="parameter">tablename</replaceable> (<replaceabl
<entry>text</entry>
<entry>Variable unlimited length</entry>
</row>
</tbody>
<row>
<entry>bytea</entry>
<entry>binary data</entry>
</row>
</tbody>
</tgroup>
</table>
@ -829,6 +839,19 @@ CREATE TABLE <replaceable class="parameter">tablename</replaceable> (<replaceabl
standard, many other RDBMS packages have it as well.
</para>
<para>
The <type>bytea</type> data type allows storage of binary data,
specifically allowing storage of NULLs which are entered as
<literal>'\\000'</>. The first backslash is interpreted by the
single quotes, and the second is recognized by <type>bytea</> and
preceeds a three digit octal value. For a similar reason, a
backslash must be entered into a field as <literal>'\\\\'</> or
<literal>'\\134'</>. You may also have to escape line feeds and
carriage return if your interface automatically translates these. It
can store values of any length. <type>Bytea</> is a non-standard
data type.
</para>
<para>
The storage requirement for data of these types is 4 bytes plus
the actual string, and in case of <type>character</type> plus the