diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2024-08-16 12:35:50 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2024-08-16 12:35:53 -0400 |
| commit | 6be39d77a70df52d5a0f2eb414ef9901ccf17e5a (patch) | |
| tree | 53bdc6708c641c016e674635bf87ef601873b77e /src/backend/utils/adt/timestamp.c | |
| parent | 108d2adb9e9e084cd57bf514d06ef4b954719ffa (diff) | |
Fix extraction of week and quarter fields from intervals.
"EXTRACT(WEEK FROM interval_value)" formerly threw an error.
Define it as "tm->tm_mday / 7". (With C99 division semantics,
this gives consistent results for negative intervals.)
"EXTRACT(QUARTER FROM interval_value)" has been implemented
all along, but it formerly gave extremely strange results for
negative intervals. Fix it so that the output for -N months
is the negative of the output for N months.
Per bug #18348 from Michael Bondarenko and subsequent discussion.
Discussion: https://postgr.es/m/18348-b097a3587dfde8a4@postgresql.org
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
| -rw-r--r-- | src/backend/utils/adt/timestamp.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 43800addf48..db9eea90982 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -5899,6 +5899,7 @@ NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative) case DTK_MILLISEC: case DTK_SECOND: case DTK_MINUTE: + case DTK_WEEK: case DTK_MONTH: case DTK_QUARTER: return 0.0; @@ -6018,12 +6019,27 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric) intresult = tm->tm_mday; break; + case DTK_WEEK: + intresult = tm->tm_mday / 7; + break; + case DTK_MONTH: intresult = tm->tm_mon; break; case DTK_QUARTER: - intresult = (tm->tm_mon / 3) + 1; + + /* + * We want to maintain the rule that a field extracted from a + * negative interval is the negative of the field's value for + * the sign-reversed interval. The broken-down tm_year and + * tm_mon aren't very helpful for that, so work from + * interval->month. + */ + if (interval->month >= 0) + intresult = (tm->tm_mon / 3) + 1; + else + intresult = -(((-interval->month % MONTHS_PER_YEAR) / 3) + 1); break; case DTK_YEAR: |