Ron Mayer wrote:
Ron Mayer wrote:
> Tom Lane wrote:
>> In fact, given that we are now
>> somewhat SQL-compliant on interval input, a GUC that selected
>> PG traditional, SQL-standard, or ISO 8601 interval output format seems
>> like it could be a good idea.
Attached are updated versions of the Interval patches ...
# Patch 2:
ISO 8601 Formatted Interval Input and Output
This patch adds another IntervalStyle 'iso_8601' to output ISO 8601
Time Intervals of the "format with designators". These are a bit
more flexible than Sql Standard intervals in that (like postgres)
they can express both years and days in the same interval value.
Reason for the patch:SQL Standard Intervals are limited compared to
postgres in what they allow (no mixed year-month and day-time
components). ISO8601 intervals allow such intervals and are easier
for machines to parse than the traditional postgres formats.
This patch depends on the IntervalStyle patch mentioned above.
*** a/doc/src/sgml/datatype.sgml
--- b/doc/src/sgml/datatype.sgml
***************
*** 1975,1980 **** January 8 04:05:06 1999 PST
--- 1975,1996 ----
</para>
<para>
+ Alternatively, <type>interval</type> values can be written as
+ ISO 8601 time intervals, using the "Format with time-unit designators",
+ or PnYnMnDTnHnMnS. This format always starts with the character
+ <literal>'P'</>, followed by a string of values followed by single
+ character time-unit designators. A <literal>'T'</> separates the
+ date and time parts of the interval.
+ In this format, <literal>'n'</> gets replaced by a number, and
+ <literal>Y</> represents years,
+ <literal>M</> (in the date part) months,
+ <literal>D</> months,
+ <literal>H</> hours,
+ <literal>M</> (in the time part) minutes,
+ and <literal>S</> seconds.
+ </para>
+
+ <para>
Internally <type>interval</> values are stored as months, days,
and seconds. This is done because the number of days in a month
varies, and a day can have 23 or 25 hours if a daylight savings
***************
*** 2224,2230 **** January 8 04:05:06 1999 PST
<para>
The output format of the interval types can be set to one of the
! three styles <literal>sql_standard</>,
<literal>postgres</>, or <literal>postgres_verbose</>.
The default is the <literal>postgres</> format.
<xref
--- 2240,2246 ----
<para>
The output format of the interval types can be set to one of the
! four styles <literal>sql_standard</>, <literal>iso_8601</>,
<literal>postgres</>, or <literal>postgres_verbose</>.
The default is the <literal>postgres</> format.
<xref
***************
*** 2244,2249 **** January 8 04:05:06 1999 PST
--- 2260,2281 ----
</para>
<para>
+ The <literal>iso_8601</> style will output ISO 8601
+ time intervals using the "format with time-unit designators"
+ This format always starts with the character
+ <literal>'P'</>, followed by a string of values followed by single
+ character time-unit designators. A <literal>'T'</> separates the
+ date and time parts of the interval.
+ In this format, <literal>'n'</> gets replaced by a number, and
+ <literal>Y</> represents years,
+ <literal>M</> (in the date part) months,
+ <literal>D</> months,
+ <literal>H</> hours,
+ <literal>M</> (in the time part) minutes,
+ and <literal>S</> seconds.
+ </para>
+
+ <para>
The <literal>postgres</> style will output intervals that match
the style PostgreSQL 8.3 outputed when the <xref linkend="guc-datestyle">
parameter was set to <literal>ISO</>.
***************
*** 2274,2279 **** January 8 04:05:06 1999 PST
--- 2306,2317 ----
<entry>-1-2 +3 -4:05:06</entry>
</row>
<row>
+ <entry>iso_8601</entry>
+ <entry>P1Y2M</entry>
+ <entry>P3DT4H5M6</entry>
+ <entry>P-1Y-2M3DT-4H-5M-6</entry>
+ </row>
+ <row>
<entry>postgres</entry>
<entry>1 year 2 mons</entry>
<entry>3 days 04:05:06</entry>
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 248,253 **** assign_intervalstyle(const char *value, bool doit, GucSource source)
--- 248,257 ----
{
newIntervalStyle = INTSTYLE_SQL_STANDARD;
}
+ else if (pg_strcasecmp(value, "iso_8601") == 0)
+ {
+ newIntervalStyle = INTSTYLE_ISO_8601;
+ }
else
{
ereport(GUC_complaint_elevel(source),
*** a/src/backend/utils/adt/datetime.c
--- b/src/backend/utils/adt/datetime.c
***************
*** 2723,2728 **** DecodeSpecial(int field, char *lowtoken, int *val)
--- 2723,2865 ----
}
+ /*
+ * Small helper functions to avoid cut&paste code in DecodeIso8601Interval
+ */
+ static void
+ adjust_fractional_seconds(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
+ {
+ int sec;
+ if (fval == 0) return;
+ fval *= scale;
+ sec = fval;
+ tm->tm_sec += sec;
+ #ifdef HAVE_INT64_TIMESTAMP
+ *fsec += rint((fval - sec) * 1000000);
+ #else
+ *fsec += (fval - sec);
+ #endif
+ }
+
+ static void
+ adjust_fractional_days(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
+ {
+ int extra_days;
+ if (fval == 0) return;
+ fval *= scale;
+ extra_days = fval;
+ tm->tm_mday += extra_days;
+ fval -= extra_days;
+ adjust_fractional_seconds(fval,tm,fsec, SECS_PER_DAY);
+ }
+
+
+ /* DecodeISO8601Interval()
+ * Decode an ISO 8601 "Representation of time-interval by
+ * duration only.... basic extended format" from ISO 8601 section 5.5.4.2
+ *
+ * Examples: P1D for 1 day
+ * PT1H for 1 hour
+ * P2Y6M7DT1H30M for 2 years, 6 months, 7 days 1 hour 30 min
+ *
+ * Returns DTERR_BAD_FORMAT if the field is not of this type.
+ *
+ * A couple exceptions from the spec:
+ * - a week field ('W') may coexist with other units
+ * - allows decimals in fields other than the least significant unit.
+ */
+ int
+ DecodeISO8601Interval(char *str, struct pg_tm * tm, fsec_t *fsec)
+ {
+ char unit;
+ int val;
+ double fval;
+ int datepart = true;
+ int negative = false;
+
+ tm->tm_year = 0;
+ tm->tm_mon = 0;
+ tm->tm_mday = 0;
+ tm->tm_hour = 0;
+ tm->tm_min = 0;
+ tm->tm_sec = 0;
+ *fsec = 0;
+
+ if (strlen(str)<3 || !(str[0] == 'P'))
+ {
+ return DTERR_BAD_FORMAT;
+ }
+ str++;
+
+ while (*str)
+ {
+ if (*str == 'T') /* T indicates the beginning of the time part */
+ {
+ datepart = false;
+ str++;
+ continue;
+ }
+ if (! (isdigit(*str) || *str == '-' || *str=='.') )
+ return DTERR_BAD_FORMAT;
+
+ negative = (*str == '-');
+ fval = strtod(str, &str);
+ val = fval;
+ fval = fval - val;
+ unit = *str;
+ str++;
+
+ if (datepart)
+ {
+ switch (unit) /* Y M D W */
+ {
+ case 'D':
+ tm->tm_mday += val;
+ adjust_fractional_seconds(fval,tm,fsec, SECS_PER_DAY);
+ break;
+ case 'W':
+ tm->tm_mday += val * 7;
+ adjust_fractional_days(fval,tm,fsec,7);
+ break;
+ case 'M':
+ tm->tm_mon += val;
+ adjust_fractional_days(fval,tm,fsec,DAYS_PER_MONTH);
+ break;
+ case 'Y':
+ tm->tm_year += val;
+ if (fval != 0)
+ tm->tm_mon += (fval * 12);
+ break;
+ default:
+ return DTERR_BAD_FORMAT; /* not a vald ISO8601 date unit prefix */
+ }
+ }
+ else
+ {
+ switch (unit) /* H M S */
+ {
+ case 'S':
+ tm->tm_sec += val;
+ adjust_fractional_seconds(fval,tm,fsec,1);
+ break;
+ case 'M':
+ tm->tm_min += val;
+ adjust_fractional_seconds(fval,tm,fsec,SECS_PER_MINUTE);
+ break;
+ case 'H':
+ tm->tm_hour += val;
+ adjust_fractional_seconds(fval,tm,fsec,SECS_PER_HOUR);
+ break;
+ default:
+ return DTERR_BAD_FORMAT; /* not a vald ISO8601 time unit prefix */
+ }
+ }
+ }
+ return 0;
+ }
+
+
+
/* DecodeInterval()
* Interpret previously parsed fields for general time interval.
* Returns 0 if successful, DTERR code if bogus input detected.
***************
*** 3621,3648 **** EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style,
return TRUE;
}
! /*
! * Small helper funciton to avoid copy&paste in EncodeInterval below
*/
static void
! AppendSeconds(char * cp,int sec, fsec_t fsec)
{
if (fsec==0)
{
! sprintf(cp, "%02d", abs(sec));
}
else
{
#ifdef HAVE_INT64_TIMESTAMP
! sprintf(cp, "%02d.%06d", sec, Abs(fsec));
#else
! sprintf(cp, "%012.9f", fabs(sec + fsec));
#endif
TrimTrailingZeros(cp);
}
}
/* EncodeInterval()
* Interpret time structure as a delta time and convert to string.
*
--- 3758,3795 ----
return TRUE;
}
!
! /*
! * Small helper functions to avoid cut&paste in EncodeInterval below
*/
+
+ static char *
+ AddISO8601IntervalPart(char * cp, int value, char units)
+ {
+ if (value==0) return cp;
+ return cp + sprintf(cp,"%d%c",value,units);
+ }
+
static void
! AppendSeconds(char * cp,int sec, fsec_t fsec, bool fillzeros)
{
if (fsec==0)
{
! sprintf(cp, fillzeros ? "%02d" : "%d" , abs(sec));
}
else
{
#ifdef HAVE_INT64_TIMESTAMP
! sprintf(cp, fillzeros ? "%02d.%06d" : "%d.%06d", abs(sec), abs(fsec));
#else
! sprintf(cp, fillzeros ? "%09.6f" : "%.6f", fabs(sec + fsec));
#endif
TrimTrailingZeros(cp);
}
}
+
/* EncodeInterval()
* Interpret time structure as a delta time and convert to string.
*
***************
*** 3734,3740 **** EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
year_sign,abs(year),abs(mon),
day_sign,abs(mday),
sec_sign,abs(hour),abs(min));
! AppendSeconds(cp,sec,fsec);
}
else if (has_year_month)
{
--- 3881,3887 ----
year_sign,abs(year),abs(mon),
day_sign,abs(mday),
sec_sign,abs(hour),abs(min));
! AppendSeconds(cp,sec,fsec,true);
}
else if (has_year_month)
{
***************
*** 3743,3758 **** EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
else if (has_day)
{
cp += sprintf(cp,"%d %d:%02d:",mday,hour,min);
! AppendSeconds(cp,sec,fsec);
}
else
{
cp += sprintf(cp,"%d:%02d:",hour,min);
! AppendSeconds(cp,sec,fsec);
}
break;
}
/* compatible with postgresql 8.3 when DateStyle = 'iso' */
case INTSTYLE_POSTGRES:
if (tm->tm_year != 0)
--- 3890,3932 ----
else if (has_day)
{
cp += sprintf(cp,"%d %d:%02d:",mday,hour,min);
! AppendSeconds(cp,sec,fsec,true);
}
else
{
cp += sprintf(cp,"%d:%02d:",hour,min);
! AppendSeconds(cp,sec,fsec,true);
}
break;
}
+ /* ISO 8601 "time-intervals by duration only */
+ case INTSTYLE_ISO_8601:
+ if ((year == 0) && (mon == 0) && (mday == 0) &&
+ (hour == 0) && (min == 0) && (sec == 0) && (fsec == 0))
+ {
+ sprintf(cp,"PT0S");
+ break;
+ }
+ cp += sprintf(cp,"P");
+ cp = AddISO8601IntervalPart(cp,year,'Y');
+ cp = AddISO8601IntervalPart(cp,mon ,'M');
+ cp = AddISO8601IntervalPart(cp,mday,'D');
+ if ((hour != 0) || (min != 0) || (sec != 0) || (fsec != 0))
+ {
+ cp += sprintf(cp,"T");
+ }
+ cp = AddISO8601IntervalPart(cp,hour,'H');
+ cp = AddISO8601IntervalPart(cp,min ,'M');
+ if ((sec != 0) || (fsec != 0))
+ {
+ cp += sprintf(cp, "%s", (sec<0 || fsec<0) ? "-" : "");
+ AppendSeconds(cp,sec,fsec,false);
+ cp += strlen(cp);
+ cp += sprintf(cp,"S");
+ }
+ break;
+
/* compatible with postgresql 8.3 when DateStyle = 'iso' */
case INTSTYLE_POSTGRES:
if (tm->tm_year != 0)
*** a/src/backend/utils/adt/timestamp.c
--- b/src/backend/utils/adt/timestamp.c
***************
*** 627,632 **** interval_in(PG_FUNCTION_ARGS)
--- 627,635 ----
ftype, MAXDATEFIELDS, &nf);
if (dterr == 0)
dterr = DecodeInterval(field, ftype, nf, range, &dtype, tm, &fsec);
+ if (dterr == DTERR_BAD_FORMAT)
+ dterr = DecodeISO8601Interval(str, tm, &fsec);
+
if (dterr != 0)
{
if (dterr == DTERR_FIELD_OVERFLOW)
*** a/src/bin/psql/tab-complete.c
--- b/src/bin/psql/tab-complete.c
***************
*** 1956,1963 **** psql_completion(char *text, int start, int end)
else if (pg_strcasecmp(prev2_wd, "IntervalStyle") == 0)
{
static const char *const my_list[] =
! {"postgres","postgres_verbose", "sql_standard", NULL};
!
COMPLETE_WITH_LIST(my_list);
}
else if (pg_strcasecmp(prev2_wd, "GEQO") == 0)
--- 1956,1962 ----
else if (pg_strcasecmp(prev2_wd, "IntervalStyle") == 0)
{
static const char *const my_list[] =
! {"postgres","postgres_verbose", "sql_standard", "iso_8601", NULL};
COMPLETE_WITH_LIST(my_list);
}
else if (pg_strcasecmp(prev2_wd, "GEQO") == 0)
*** a/src/include/miscadmin.h
--- b/src/include/miscadmin.h
***************
*** 197,206 **** extern int DateOrder;
--- 197,208 ----
* INTSTYLE_POSTGRES Like Postgres8.3 when DateStyle = 'iso'
* INTSTYLE_POSTGRES_VERBOSE Like Postgres8.3 when DateStyle = 'sql'
* INTSTYLE_SQL_STANDARD SQL standard interval literals
+ * INTSTYLE_ISO_8601 Specifies ISO-8601-basic formatted intervals
*/
#define INTSTYLE_POSTGRES 0
#define INTSTYLE_POSTGRES_VERBOSE 1
#define INTSTYLE_SQL_STANDARD 2
+ #define INTSTYLE_ISO_8601 3
extern int IntervalStyle;
*** a/src/include/utils/datetime.h
--- b/src/include/utils/datetime.h
***************
*** 292,297 **** extern int DecodeTimeOnly(char **field, int *ftype,
--- 292,300 ----
extern int DecodeInterval(char **field, int *ftype,
int nf, int range, int *dtype,
struct pg_tm * tm, fsec_t *fsec);
+ extern int DecodeISO8601Interval(char *str,
+ struct pg_tm * tm, fsec_t *fsec);
+
extern void DateTimeParseError(int dterr, const char *str,
const char *datatype);
*** a/src/test/regress/expected/interval.out
--- b/src/test/regress/expected/interval.out
***************
*** 632,634 **** SELECT interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds',
--- 632,663 ----
+1-2 -3 +4:05:06.789 | -1-2 +3 -4:05:06.789
(1 row)
+ -- test outputting iso8601 intervals
+ SET IntervalStyle to iso_8601;
+ select interval '0' AS "zero",
+ interval '1-2' AS "a year 2 months",
+ interval '1 2:03:04' AS "a bit over a day",
+ interval '2:03:04.45679' AS "a bit over 2 hours",
+ (interval '1-2' + interval '3 4:05:06.7') AS "all fields",
+ (interval '1-2' - interval '3 4:05:06.7') AS "mixed sign",
+ (- interval '1-2' + interval '3 4:05:06.7') AS "negative"
+ ;
+ zero | a year 2 months | a bit over a day | a bit over 2 hours | all fields | mixed sign | negative
+ ------+-----------------+------------------+--------------------+-------------------+-----------------------+---------------------
+ PT0S | P1Y2M | P1DT2H3M4S | PT2H3M4.45679S | P1Y2M3DT4H5M6.70S | P1Y2M-3DT-4H-5M-6.70S | P-1Y-2M3DT4H5M6.70S
+ (1 row)
+
+ -- test inputting iso8601 intervals
+ SET IntervalStyle to sql_standard;
+ select interval 'P0Y' AS "zero",
+ interval 'P1Y2M' AS "a year 2 months",
+ interval 'P1W' AS "a week",
+ interval 'P1DT2H3M4S' AS "a bit over a day",
+ interval 'P1Y2M3DT4H5M6.7S' AS "all fields",
+ interval 'P-1Y-2M-3DT-4H-5M-6.7S' AS "negative",
+ interval 'PT-0.1S' AS "fractional second";
+ zero | a year 2 months | a week | a bit over a day | all fields | negative | fractional second
+ ------+-----------------+-----------+------------------+---------------------+---------------------+-------------------
+ 0 | 1-2 | 7 0:00:00 | 1 2:03:04 | +1-2 +3 +4:05:06.70 | -1-2 -3 -4:05:06.70 | -0:00:00.10
+ (1 row)
+
*** a/src/test/regress/sql/interval.sql
--- b/src/test/regress/sql/interval.sql
***************
*** 190,192 **** SELECT interval '0' AS "zero",
--- 190,213 ----
-- test a couple non-standard interval values too
SELECT interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds',
- interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds';
+
+ -- test outputting iso8601 intervals
+ SET IntervalStyle to iso_8601;
+ select interval '0' AS "zero",
+ interval '1-2' AS "a year 2 months",
+ interval '1 2:03:04' AS "a bit over a day",
+ interval '2:03:04.45679' AS "a bit over 2 hours",
+ (interval '1-2' + interval '3 4:05:06.7') AS "all fields",
+ (interval '1-2' - interval '3 4:05:06.7') AS "mixed sign",
+ (- interval '1-2' + interval '3 4:05:06.7') AS "negative"
+ ;
+
+ -- test inputting iso8601 intervals
+ SET IntervalStyle to sql_standard;
+ select interval 'P0Y' AS "zero",
+ interval 'P1Y2M' AS "a year 2 months",
+ interval 'P1W' AS "a week",
+ interval 'P1DT2H3M4S' AS "a bit over a day",
+ interval 'P1Y2M3DT4H5M6.7S' AS "all fields",
+ interval 'P-1Y-2M-3DT-4H-5M-6.7S' AS "negative",
+ interval 'PT-0.1S' AS "fractional second";
--
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