Fix wrong week returnded by date_trunc('week') for early dates in

January --- would return wrong year for 2005-01-01 and 2006-01-01.

per report from Robert Creager.

Backpatch to 8.0.X.
This commit is contained in:
Bruce Momjian 2005-04-01 14:25:23 +00:00
parent a70574d803
commit 9e9724e8bd
2 changed files with 34 additions and 6 deletions

View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.243 2005/03/30 04:52:49 neilc Exp $
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.244 2005/04/01 14:25:22 momjian Exp $
PostgreSQL documentation
-->
@ -5472,6 +5472,12 @@ SELECT EXTRACT(SECOND FROM TIME '17:12:28.5');
week starts on Monday.) In other words, the first Thursday of
a year is in week 1 of that year. (for <type>timestamp</type> values only)
</para>
<para>
Because of this, it is possible for early January dates to be part of the
52nd or 53rd week of the previous year. For example, <literal>2005-01-01</>
is part of the 53rd week of year 2004, and <literal>2006-01-01</> is part of
the 52nd week of year 2005.
</para>
<screen>
SELECT EXTRACT(WEEK FROM TIMESTAMP '2001-02-16 20:38:40');

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.117 2004/12/31 22:01:22 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.118 2005/04/01 14:25:23 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -2754,12 +2754,23 @@ timestamp_trunc(PG_FUNCTION_ARGS)
switch (val)
{
case DTK_WEEK:
isoweek2date(date2isoweek(tm->tm_year, tm->tm_mon, tm->tm_mday), &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
{
int woy;
woy = date2isoweek(tm->tm_year, tm->tm_mon, tm->tm_mday);
/*
* If it is week 52/53 and the month is January,
* then the week must belong to the previous year.
*/
if (woy >= 52 && tm->tm_mon == 1)
--tm->tm_year;
isoweek2date(woy, &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
tm->tm_hour = 0;
tm->tm_min = 0;
tm->tm_sec = 0;
fsec = 0;
break;
}
case DTK_MILLENNIUM:
/* see comments in timestamptz_trunc */
if (tm->tm_year > 0)
@ -2874,13 +2885,24 @@ timestamptz_trunc(PG_FUNCTION_ARGS)
switch (val)
{
case DTK_WEEK:
isoweek2date(date2isoweek(tm->tm_year, tm->tm_mon, tm->tm_mday), &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
{
int woy;
woy = date2isoweek(tm->tm_year, tm->tm_mon, tm->tm_mday);
/*
* If it is week 52/53 and the month is January,
* then the week must belong to the previous year.
*/
if (woy >= 52 && tm->tm_mon == 1)
--tm->tm_year;
isoweek2date(woy, &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
tm->tm_hour = 0;
tm->tm_min = 0;
tm->tm_sec = 0;
fsec = 0;
redotz = true;
break;
}
/* one may consider DTK_THOUSAND and DTK_HUNDRED... */
case DTK_MILLENNIUM:
@ -3142,7 +3164,7 @@ date2isoweek(int year, int mon, int mday)
* Sometimes the last few days in a year will fall into the first week
* of the next year, so check for this.
*/
if (result >= 53)
if (result >= 52)
{
day4 = date2j(year + 1, 1, 4);
@ -3198,7 +3220,7 @@ date2isoyear(int year, int mon, int mday)
* Sometimes the last few days in a year will fall into the first week
* of the next year, so check for this.
*/
if (result >= 53)
if (result >= 52)
{
day4 = date2j(year + 1, 1, 4);