diff options
-rw-r--r-- | doc/src/sgml/datatype.sgml | 25 | ||||
-rw-r--r-- | src/backend/utils/adt/datetime.c | 16 | ||||
-rw-r--r-- | src/interfaces/ecpg/pgtypeslib/interval.c | 16 |
3 files changed, 26 insertions, 31 deletions
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml index 453115f942f..50a2c8e5f16 100644 --- a/doc/src/sgml/datatype.sgml +++ b/doc/src/sgml/datatype.sgml @@ -2840,15 +2840,18 @@ P <optional> <replaceable>years</replaceable>-<replaceable>months</replaceable>- </para> <para> - In the verbose input format, and in some fields of the more compact - input formats, field values can have fractional parts; for example - <literal>'1.5 week'</literal> or <literal>'01:02:03.45'</literal>. Such input is - converted to the appropriate number of months, days, and seconds - for storage. When this would result in a fractional number of - months or days, the fraction is added to the lower-order fields - using the conversion factors 1 month = 30 days and 1 day = 24 hours. - For example, <literal>'1.5 month'</literal> becomes 1 month and 15 days. - Only seconds will ever be shown as fractional on output. + Field values can have fractional parts: for example, <literal>'1.5 + weeks'</literal> or <literal>'01:02:03.45'</literal>. However, + because interval internally stores only three integer units (months, + days, microseconds), fractional units must be spilled to smaller + units. Fractional parts of units greater than months is rounded to + be an integer number of months, e.g. <literal>'1.5 years'</literal> + becomes <literal>'1 year 6 mons'</literal>. Fractional parts of + weeks and days are computed to be an integer number of days and + microseconds, assuming 30 days per month and 24 hours per day, e.g., + <literal>'1.75 months'</literal> becomes <literal>1 mon 22 days + 12:00:00</literal>. Only seconds will ever be shown as fractional + on output. </para> <para> @@ -2892,10 +2895,10 @@ P <optional> <replaceable>years</replaceable>-<replaceable>months</replaceable>- <para> Internally <type>interval</type> values are stored as months, days, - and seconds. This is done because the number of days in a month + and microseconds. 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 time adjustment is involved. The months and days fields are integers - while the seconds field can store fractions. Because intervals are + while the microseconds field can store fractional seconds. Because intervals are usually created from constant strings or <type>timestamp</type> subtraction, this storage method works well in most cases, but can cause unexpected results: diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c index 54ae632de24..cb3fa85892b 100644 --- a/src/backend/utils/adt/datetime.c +++ b/src/backend/utils/adt/datetime.c @@ -3306,29 +3306,25 @@ DecodeInterval(char **field, int *ftype, int nf, int range, case DTK_YEAR: tm->tm_year += val; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); tmask = DTK_M(YEAR); break; case DTK_DECADE: tm->tm_year += val * 10; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 10; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 10); tmask = DTK_M(DECADE); break; case DTK_CENTURY: tm->tm_year += val * 100; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 100; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 100); tmask = DTK_M(CENTURY); break; case DTK_MILLENNIUM: tm->tm_year += val * 1000; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 1000; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 1000); tmask = DTK_M(MILLENNIUM); break; @@ -3565,7 +3561,7 @@ DecodeISO8601Interval(char *str, { case 'Y': tm->tm_year += val; - tm->tm_mon += (fval * MONTHS_PER_YEAR); + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); break; case 'M': tm->tm_mon += val; @@ -3601,7 +3597,7 @@ DecodeISO8601Interval(char *str, return DTERR_BAD_FORMAT; tm->tm_year += val; - tm->tm_mon += (fval * MONTHS_PER_YEAR); + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); if (unit == '\0') return 0; if (unit == 'T') diff --git a/src/interfaces/ecpg/pgtypeslib/interval.c b/src/interfaces/ecpg/pgtypeslib/interval.c index 02b3c472233..a7e530cb5d2 100644 --- a/src/interfaces/ecpg/pgtypeslib/interval.c +++ b/src/interfaces/ecpg/pgtypeslib/interval.c @@ -155,7 +155,7 @@ DecodeISO8601Interval(char *str, { case 'Y': tm->tm_year += val; - tm->tm_mon += (fval * MONTHS_PER_YEAR); + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); break; case 'M': tm->tm_mon += val; @@ -191,7 +191,7 @@ DecodeISO8601Interval(char *str, return DTERR_BAD_FORMAT; tm->tm_year += val; - tm->tm_mon += (fval * MONTHS_PER_YEAR); + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); if (unit == '\0') return 0; if (unit == 'T') @@ -528,29 +528,25 @@ DecodeInterval(char **field, int *ftype, int nf, /* int range, */ case DTK_YEAR: tm->tm_year += val; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR); tmask = (fmask & DTK_M(YEAR)) ? 0 : DTK_M(YEAR); break; case DTK_DECADE: tm->tm_year += val * 10; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 10; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 10); tmask = (fmask & DTK_M(YEAR)) ? 0 : DTK_M(YEAR); break; case DTK_CENTURY: tm->tm_year += val * 100; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 100; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 100); tmask = (fmask & DTK_M(YEAR)) ? 0 : DTK_M(YEAR); break; case DTK_MILLENNIUM: tm->tm_year += val * 1000; - if (fval != 0) - tm->tm_mon += fval * MONTHS_PER_YEAR * 1000; + tm->tm_mon += rint(fval * MONTHS_PER_YEAR * 1000); tmask = (fmask & DTK_M(YEAR)) ? 0 : DTK_M(YEAR); break; |