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<chapter id="functions">

<title>Functions and Operators</title>

Also there are some pre-defined conversions. See <xref

linkend="conversion-names"> for available conversions.

</entry>

<entry><literal>convert('text_in_utf8', 'UTF8', 'LATIN1')</literal></entry>

<entry><literal>convert('text_in_utf8', 'UTF8', 'LATIN1')</literal></entry>

<entry><literal>text_in_utf8</literal> represented in ISO 8859-1 encoding</entry>

</row>

is specified by <parameter>src_encoding</parameter>. The

<parameter>string</parameter> must be valid in this encoding.

</entry>

<entry><literal>convert_from('text_in_utf8', 'UTF8')</literal></entry>

<entry><literal>convert_from('text_in_utf8', 'UTF8')</literal></entry>

<entry><literal>text_in_utf8</literal> represented in the current database encoding</entry>

</row>

<entry>

Convert string to <parameter>dest_encoding</parameter>.

</entry>

<entry><literal>convert_to('some text', 'UTF8')</literal></entry>

<entry><literal>convert_to('some text', 'UTF8')</literal></entry>

<entry><literal>some text</literal> represented in the UTF8 encoding</entry>

</row>

<literal>Escape</> merely outputs null bytes as <literal>\000</> and

doubles backslashes.

</entry>

<entry><literal>encode(E'123\\000\\001', 'base64')</literal></entry>

<entry><literal>encode(E'123\\000\\001', 'base64')</literal></entry>

<entry><literal>MTIzAAE=</literal></entry>

</row>

in an <acronym>SQL</acronym> statement string.

Embedded single-quotes and backslashes are properly doubled.

</entry>

<entry><literal>quote_literal('O\'Reilly')</literal></entry>

<entry><literal>quote_literal('O\'Reilly')</literal></entry>

<entry><literal>'O''Reilly'</literal></entry>

</row>

<entry>Replace all occurrences in <parameter>string</parameter> of substring

<parameter>from</parameter> with substring <parameter>to</parameter>

</entry>

<entry><literal>replace('abcdefabcdef', 'cd', 'XX')</literal></entry>

<entry><literal>replace('abcdefabcdef', 'cd', 'XX')</literal></entry>

<entry><literal>abXXefabXXef</literal></entry>

</row>

<entry><literal><function>octet_length</function>(<parameter>string</parameter>)</literal></entry>

<entry><type>int</type></entry>

<entry>Number of bytes in binary string</entry>

<entry><literal>octet_length(E'jo\\000se'::bytea)</literal></entry>

<entry><literal>octet_length(E'jo\\000se'::bytea)</literal></entry>

<entry><literal>5</literal></entry>

</row>