1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
-
- This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
- project.
-
- Copyright (C) 1998-2018 OpenLink Software
-
- This project is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the
- Free Software Foundation; only version 2 of the License, dated June 1991.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-
-
-->
<refentry id="fn_blob_to_string">
<refmeta>
<refentrytitle>blob_to_string</refentrytitle>
<refmiscinfo>string</refmiscinfo>
</refmeta>
<refnamediv>
<refname>blob_to_string</refname>
<refpurpose>Convert a blob to string</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis id="fsyn_blob_to_string">
<funcprototype id="fproto_blob_to_string">
<funcdef>varchar <function>blob_to_string</function></funcdef>
<paramdef>in <parameter>blob</parameter>any</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id="desc_blob_to_string">
<title>Description</title>
<para>Although primarily used for converting <type>blobs</type> (<type>long varbinary</type>,
<type>long varchar</type>) to <type>string</type>, <function>blob_to_string</function>
may also be used to convert from <type>wide string</type>, <type>persistent
XML (XPER)</type> and <type>string_output streams</type>. If the data being
converted is longer than maximum length of a <type>string</type>,
<function>blob_to_string</function> will signal an error.</para>
<note><title>Note</title>
<para>This function is equivalent to <programlisting>cast (x as varchar)</programlisting>.
Using <function>cast</function> is preferred.</para>
</note>
</refsect1>
<refsect1 id="params_blob_to_string"><title>Parameters</title>
<refsect2><title><parameter>blob</parameter></title>
<para><type>blob handle</type> (long varbinary or long varchar), <type>string_output</type> or <type>XPER</type> (persistent XML)</para>
</refsect2>
</refsect1>
<refsect1 id="ret_blob_to_string"><title>Return Types</title>
<para><type>Varchar</type> contents of <parameter>blob</parameter>.</para>
</refsect1>
<refsect1 id="errors_blob_to_string"><title>Errors</title>
<table><title>Errors signalled by <function>blob_to_string</function></title>
<tgroup cols="4">
<thead><row><entry>SQLState</entry><entry>Error Code</entry><entry>Error Message</entry><entry>Description</entry></row></thead>
<tbody>
<row>
<entry><errorcode>22023</errorcode></entry>
<entry><errorcode>SR068</errorcode></entry>
<entry><errorname>XML tree cannot be used as argument of blob_to_string</errorname></entry>
<entry></entry>
</row>
<row>
<entry><errorcode>22001</errorcode></entry>
<entry><errorcode>SR069</errorcode></entry>
<entry><errorname>Attempt to convert a persistent XML document longer than VARCHAR maximum in blob_to_string</errorname></entry>
<entry></entry>
</row>
<row>
<entry><errorcode>22023</errorcode></entry>
<entry><errorcode>SR070</errorcode></entry>
<entry><errorname>blob_to_string requires a blob as argument</errorname></entry>
<entry></entry>
</row>
<row>
<entry><errorcode>22023</errorcode></entry>
<entry><errorcode>SR071</errorcode></entry>
<entry><errorname>Blob argument to blob_to_string must be a non-interactive blob</errorname></entry>
<entry></entry>
</row>
<row>
<entry><errorcode>22001</errorcode></entry>
<entry><errorcode>SR072</errorcode></entry>
<entry><errorname>Blob too long for the string.</errorname></entry>
<entry></entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1 id="examples_blob_to_string"><title>Examples</title>
<example id="ex_blob_to_string"><title>Various conversions</title>
<screen>SQL> use Demo;
Done. -- 20 msec.
SQL> select blob_to_string (Description) from Categories;
callret
VARCHAR
_______________________________________________________________________________
Soft drinks, coffees, teas, beers, and ales
Sweet and savory sauces, relishes, spreads, and seasonings
Desserts, candies, and sweet breads
Cheeses
Breads, crackers, pasta, and cereal
Prepared meats
Dried fruit and bean curd
Seaweed and fish
8 Rows. -- 37 msec.
SQL>
</screen>
</example>
</refsect1>
<refsect1 id="seealso_blob_to_string"><title>See Also</title>
<para><link linkend="dtcasting">Casting</link>, <link linkend="fn_string_output"><function>string_output</function></link>.</para>
</refsect1>
</refentry>
|
