Clarify documentation for "day of the week" handling for to_char() and

EXTRACT().
This commit is contained in:
Bruce Momjian 2007-02-19 18:20:06 +00:00
parent 107062e008
commit 70007b4dd5

View file

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.362 2007/02/19 17:41:38 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.363 2007/02/19 18:20:06 momjian Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@ -4617,11 +4617,11 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
</row>
<row>
<entry><literal>D</literal></entry>
<entry>day of week (1-7; Sunday is 1)</entry>
<entry>day of the week, Sunday(<literal>1</>) to Saturday(<literal>7</>)</entry>
</row>
<row>
<entry><literal>ID</literal></entry>
<entry>ISO day of week (1-7; Monday is 1)</entry>
<entry>ISO day of the week, Monday(<literal>1</>) to Sunday(<literal>7</>)</entry>
</row>
<row>
<entry><literal>W</literal></entry>
@ -4844,9 +4844,11 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
</listitem>
<listitem>
<para><function>to_char</function>'s day of the week numbering
(see the 'D' formatting pattern) is different from that of the
<function>extract</function> function.
<para>
<function>to_char(..., 'ID')</function>'s day of the week numbering
matches the <function>extract('isodow', ...)</function> function.
<function>to_char(..., 'D')</function>'s does not match
<function>extract('dow', ...)</function>'s day numbering.
</para>
</listitem>
@ -5741,8 +5743,9 @@ SELECT EXTRACT(DOW FROM TIMESTAMP '2001-02-16 20:38:40');
<lineannotation>Result: </lineannotation><computeroutput>5</computeroutput>
</screen>
<para>
Note that <function>extract</function>'s day of the week numbering is
different from that of the <function>to_char</function> function.
Note that <function>extract</function>'s day of the week numbering
is different from that of the <function>to_char(...,
'D')</function> function.
</para>
</listitem>