Here is a patch that allows HH and HH12 to be used with interval, and
hence time. I added documentation to warn users that using those with
intervals are mapped to single-day values.
I will soon apply this to HEAD and 8.1.X.
---------------------------------------------------------------------------
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I see your issue with HH/HH24, but I wanted this to work:
>
> > test=> select to_char('14 hours'::interval, 'HH');
> > to_char
> > ---------
> > 14
> > (1 row)
>
> > With the HH/HH24 change that is going to return 2. Do interval folks
> > know they would have to use HH24 for intervals?
>
> Dunno if they know it, but they always had to do it that way before 8.1,
> so it's not a change to require it. I get this in everything back to
> 7.2:
>
> regression=# select to_char('14 hours'::interval, 'HH');
> to_char
> ---------
> 02
> (1 row)
>
> regression=# select to_char('14 hours'::interval, 'HH24');
> to_char
> ---------
> 14
> (1 row)
>
> and I don't see anything especially wrong with that behavior, as long as
> it's documented.
>
> > Should we subtract 12 only if the time is < 24. That also seems
> > strange. Also, a zero hour interval to HH would return 12, not 0.
>
> Offhand I'd vote for making the HH code use a "mod 12" calculation,
> and making AM/PM depend on the value "mod 24". This gives at least a
> slightly sane behavior for intervals > 24 hours.
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Have you searched our list archives?
>
> http://archives.postgresql.org
>
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/func.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/func.sgml,v
retrieving revision 1.296
diff -c -c -r1.296 func.sgml
*** doc/src/sgml/func.sgml 28 Nov 2005 23:18:48 -0000 1.296
--- doc/src/sgml/func.sgml 2 Dec 2005 03:51:45 -0000
***************
*** 4749,4754 ****
--- 4749,4762 ----
<function>extract</function> function.
</para>
</listitem>
+
+ <listitem>
+ <para><function>to_char(interval)</function> formats <literal>HH</> and
+ <literal>HH12</> to hours in a single day, while <literal>HH24</>
+ can output hours exceeding a single day, e.g. >24.
+ </para>
+ </listitem>
+
</itemizedlist>
</para>
Index: src/backend/utils/adt/formatting.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/formatting.c,v
retrieving revision 1.102
diff -c -c -r1.102 formatting.c
*** src/backend/utils/adt/formatting.c 22 Nov 2005 18:17:22 -0000 1.102
--- src/backend/utils/adt/formatting.c 2 Dec 2005 03:51:51 -0000
***************
*** 1722,1732 ****
{
case DCH_A_M:
case DCH_P_M:
- INVALID_FOR_INTERVAL;
if (is_to_char)
{
! strcpy(inout, ((tm->tm_hour > 11
! && tm->tm_hour < HOURS_PER_DAY) ?
P_M_STR : A_M_STR));
return strlen(p_inout);
}
else
--- 1722,1731 ----
{
case DCH_A_M:
case DCH_P_M:
if (is_to_char)
{
! strcpy(inout, (tm->tm_hour % HOURS_PER_DAY >=
HOURS_PER_DAY / 2)
! ? P_M_STR : A_M_STR);
return strlen(p_inout);
}
else
***************
*** 1742,1752 ****
break;
case DCH_AM:
case DCH_PM:
- INVALID_FOR_INTERVAL;
if (is_to_char)
{
! strcpy(inout, ((tm->tm_hour > 11
! && tm->tm_hour <
HOURS_PER_DAY) ? PM_STR : AM_STR));
return strlen(p_inout);
}
else
--- 1741,1750 ----
break;
case DCH_AM:
case DCH_PM:
if (is_to_char)
{
! strcpy(inout, (tm->tm_hour % HOURS_PER_DAY >=
HOURS_PER_DAY / 2)
! ? PM_STR : AM_STR);
return strlen(p_inout);
}
else
***************
*** 1762,1772 ****
break;
case DCH_a_m:
case DCH_p_m:
- INVALID_FOR_INTERVAL;
if (is_to_char)
{
! strcpy(inout, ((tm->tm_hour > 11
! && tm->tm_hour < HOURS_PER_DAY) ?
p_m_STR : a_m_STR));
return strlen(p_inout);
}
else
--- 1760,1769 ----
break;
case DCH_a_m:
case DCH_p_m:
if (is_to_char)
{
! strcpy(inout, (tm->tm_hour % HOURS_PER_DAY >=
HOURS_PER_DAY / 2)
! ? p_m_STR : a_m_STR);
return strlen(p_inout);
}
else
***************
*** 1782,1792 ****
break;
case DCH_am:
case DCH_pm:
- INVALID_FOR_INTERVAL;
if (is_to_char)
{
! strcpy(inout, ((tm->tm_hour > 11
! && tm->tm_hour <
HOURS_PER_DAY) ? pm_STR : am_STR));
return strlen(p_inout);
}
else
--- 1779,1788 ----
break;
case DCH_am:
case DCH_pm:
if (is_to_char)
{
! strcpy(inout, (tm->tm_hour % HOURS_PER_DAY >=
HOURS_PER_DAY / 2)
! ? pm_STR : am_STR);
return strlen(p_inout);
}
else
***************
*** 1804,1815 ****
case DCH_HH12:
if (is_to_char)
{
! if (is_interval)
! sprintf(inout, "%0*d", S_FM(suf) ? 0 :
2, tm->tm_hour);
! else
! sprintf(inout, "%0*d", S_FM(suf) ? 0 :
2,
! tm->tm_hour == 0 ? 12 :
! tm->tm_hour < 13 ?
tm->tm_hour : tm->tm_hour - 12);
if (S_THth(suf))
str_numth(p_inout, inout, 0);
return strlen(p_inout);
--- 1800,1808 ----
case DCH_HH12:
if (is_to_char)
{
! sprintf(inout, "%0*d", S_FM(suf) ? 0 : 2,
! tm->tm_hour % (HOURS_PER_DAY /
2) == 0 ? 12 :
! tm->tm_hour % (HOURS_PER_DAY / 2));
if (S_THth(suf))
str_numth(p_inout, inout, 0);
return strlen(p_inout);
***************
*** 2312,2318 ****
}
break;
case DCH_D:
- INVALID_FOR_INTERVAL;
if (is_to_char)
{
sprintf(inout, "%d", tm->tm_wday + 1);
--- 2305,2310 ----
---------------------------(end of broadcast)---------------------------
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