Fix to_char(), to_date(), and to_timestamp() to handle negative/BC

century specifications just like positive/AD centuries.  Previously the
behavior was either wrong or inconsistent with positive/AD handling.

Centuries without years now always assume the first year of the century,
which is now documented.
This commit is contained in:
Bruce Momjian 2012-08-07 13:34:44 -04:00
parent fbcfa90bb8
commit ac78c4178b
4 changed files with 39 additions and 22 deletions

View File

@ -5575,7 +5575,9 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
if there is a <literal>YYY</literal>, <literal>YYYY</literal> or
<literal>Y,YYY</literal> field. If <literal>CC</literal> is used with
<literal>YY</literal> or <literal>Y</literal> then the year is computed
as <literal>(CC-1)*100+YY</literal>.
as the year in the specified century. If the century is
specified but the year is not, the first year of the century
is assumed.
</para>
</listitem>

View File

@ -2640,8 +2640,15 @@ DCH_to_char(FormatNode *node, bool is_interval, TmToChar *in, char *out, Oid col
case DCH_CC:
if (is_interval) /* straight calculation */
i = tm->tm_year / 100;
else /* century 21 starts in 2001 */
else
{
if (tm->tm_year > 0)
/* Century 20 == 1901 - 2000 */
i = (tm->tm_year - 1) / 100 + 1;
else
/* Century 6BC == 600BC - 501BC */
i = tm->tm_year / 100 - 1;
}
if (i <= 99 && i >= -99)
sprintf(s, "%0*d", S_FM(n->suffix) ? 0 : 2, i);
else
@ -3465,33 +3472,41 @@ do_to_timestamp(text *date_txt, text *fmt,
/*
* If CC and YY (or Y) are provided, use YY as 2 low-order digits for
* the year in the given century. Keep in mind that the 21st century
* runs from 2001-2100, not 2000-2099.
*
* If a 4-digit year is provided, we use that and ignore CC.
* AD runs from 2001-2100, not 2000-2099; 6th century BC runs from
* 600BC to 501BC.
*/
if (tmfc.cc && tmfc.yysz <= 2)
{
if (tmfc.bc)
tmfc.cc = -tmfc.cc;
tm->tm_year = tmfc.year % 100;
if (tm->tm_year)
{
if (tmfc.cc >= 0)
tm->tm_year += (tmfc.cc - 1) * 100;
else
tm->tm_year = tmfc.cc * 100;
tm->tm_year = (tmfc.cc + 1) * 100 - tm->tm_year + 1;
}
else
/* find century year for dates ending in "00" */
tm->tm_year = tmfc.cc * 100 + ((tmfc.cc >= 0) ? 0 : 1);
}
else
/* If a 4-digit year is provided, we use that and ignore CC. */
{
tm->tm_year = tmfc.year;
if (tmfc.bc && tm->tm_year > 0)
tm->tm_year = -(tm->tm_year - 1);
}
}
else if (tmfc.cc) /* use first year of century */
tm->tm_year = (tmfc.cc - 1) * 100 + 1;
if (tmfc.bc)
{
if (tm->tm_year > 0)
tm->tm_year = -(tm->tm_year - 1);
if (tmfc.bc)
tmfc.cc = -tmfc.cc;
if (tmfc.cc >= 0)
tm->tm_year = (tmfc.cc - 1) * 100 + 1;
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_DATETIME_FORMAT),
errmsg("inconsistent use of year %04d and \"BC\"",
tm->tm_year)));
tm->tm_year = tmfc.cc * 100 + 1;
}
if (tmfc.j)

View File

@ -992,7 +992,7 @@ SELECT '' AS to_char_3, to_char(d1, 'Y,YYY YYYY YYY YY Y CC Q MM WW DDD DD D J')
| 1,997 1997 997 97 7 20 1 02 07 045 14 6 2450494
| 1,997 1997 997 97 7 20 1 02 07 046 15 7 2450495
| 1,997 1997 997 97 7 20 1 02 07 047 16 1 2450496
| 0,097 0097 097 97 7 01 1 02 07 047 16 3 1686042
| 0,097 0097 097 97 7 -1 1 02 07 047 16 3 1686042
| 0,097 0097 097 97 7 01 1 02 07 047 16 7 1756536
| 0,597 0597 597 97 7 06 1 02 07 047 16 5 1939157
| 1,097 1097 097 97 7 11 1 02 07 047 16 3 2121778
@ -1063,7 +1063,7 @@ SELECT '' AS to_char_4, to_char(d1, 'FMY,YYY FMYYYY FMYYY FMYY FMY FMCC FMQ FMMM
| 1,997 1997 997 97 7 20 1 2 7 45 14 6 2450494
| 1,997 1997 997 97 7 20 1 2 7 46 15 7 2450495
| 1,997 1997 997 97 7 20 1 2 7 47 16 1 2450496
| 0,097 97 97 97 7 1 1 2 7 47 16 3 1686042
| 0,097 97 97 97 7 -1 1 2 7 47 16 3 1686042
| 0,097 97 97 97 7 1 1 2 7 47 16 7 1756536
| 0,597 597 597 97 7 6 1 2 7 47 16 5 1939157
| 1,097 1097 97 97 7 11 1 2 7 47 16 3 2121778

View File

@ -1074,7 +1074,7 @@ SELECT '' AS to_char_3, to_char(d1, 'Y,YYY YYYY YYY YY Y CC Q MM WW DDD DD D J')
| 1,997 1997 997 97 7 20 1 02 07 045 14 6 2450494
| 1,997 1997 997 97 7 20 1 02 07 046 15 7 2450495
| 1,997 1997 997 97 7 20 1 02 07 047 16 1 2450496
| 0,097 0097 097 97 7 01 1 02 07 047 16 3 1686042
| 0,097 0097 097 97 7 -1 1 02 07 047 16 3 1686042
| 0,097 0097 097 97 7 01 1 02 07 047 16 7 1756536
| 0,597 0597 597 97 7 06 1 02 07 047 16 5 1939157
| 1,097 1097 097 97 7 11 1 02 07 047 16 3 2121778
@ -1146,7 +1146,7 @@ SELECT '' AS to_char_4, to_char(d1, 'FMY,YYY FMYYYY FMYYY FMYY FMY FMCC FMQ FMMM
| 1,997 1997 997 97 7 20 1 2 7 45 14 6 2450494
| 1,997 1997 997 97 7 20 1 2 7 46 15 7 2450495
| 1,997 1997 997 97 7 20 1 2 7 47 16 1 2450496
| 0,097 97 97 97 7 1 1 2 7 47 16 3 1686042
| 0,097 97 97 97 7 -1 1 2 7 47 16 3 1686042
| 0,097 97 97 97 7 1 1 2 7 47 16 7 1756536
| 0,597 597 597 97 7 6 1 2 7 47 16 5 1939157
| 1,097 1097 97 97 7 11 1 2 7 47 16 3 2121778