diff options
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
| -rw-r--r-- | src/backend/utils/adt/timestamp.c | 85 |
1 files changed, 73 insertions, 12 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 3f6d4315230..a38bbda9af1 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.109 2004/06/03 17:57:09 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.110 2004/08/20 03:45:13 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -2727,11 +2727,26 @@ timestamp_trunc(PG_FUNCTION_ARGS) fsec = 0; break; case DTK_MILLENNIUM: - tm->tm_year = (tm->tm_year / 1000) * 1000; + /* see comments in timestamptz_trunc */ + if (tm->tm_year > 0) + tm->tm_year = ((tm->tm_year+999) / 1000) * 1000 - 999; + else + tm->tm_year = - ((999 - (tm->tm_year-1))/1000) * 1000 + 1; case DTK_CENTURY: - tm->tm_year = (tm->tm_year / 100) * 100; + /* see comments in timestamptz_trunc */ + if (tm->tm_year > 0) + tm->tm_year = ((tm->tm_year+99) / 100) * 100 - 99; + else + tm->tm_year = - ((99 - (tm->tm_year-1))/100) * 100 + 1; case DTK_DECADE: - tm->tm_year = (tm->tm_year / 10) * 10; + /* see comments in timestamptz_trunc */ + if (val != DTK_MILLENNIUM && val != DTK_CENTURY) + { + if (tm->tm_year > 0) + tm->tm_year = (tm->tm_year / 10) * 10; + else + tm->tm_year = - ((8-(tm->tm_year-1)) / 10) * 10; + } case DTK_YEAR: tm->tm_mon = 1; case DTK_QUARTER: @@ -2830,12 +2845,33 @@ timestamptz_trunc(PG_FUNCTION_ARGS) tm->tm_sec = 0; fsec = 0; break; + /* one may consider DTK_THOUSAND and DTK_HUNDRED... */ case DTK_MILLENNIUM: - tm->tm_year = (tm->tm_year / 1000) * 1000; + /* truncating to the millennium? what is this supposed to mean? + * let us put the first year of the millennium... + * i.e. -1000, 1, 1001, 2001... + */ + if (tm->tm_year > 0) + tm->tm_year = ((tm->tm_year+999) / 1000) * 1000 - 999; + else + tm->tm_year = - ((999 - (tm->tm_year-1))/1000) * 1000 + 1; case DTK_CENTURY: - tm->tm_year = (tm->tm_year / 100) * 100; + /* truncating to the century? as above: -100, 1, 101... */ + if (tm->tm_year > 0) + tm->tm_year = ((tm->tm_year+99) / 100) * 100 - 99 ; + else + tm->tm_year = - ((99 - (tm->tm_year-1))/100) * 100 + 1; case DTK_DECADE: - tm->tm_year = (tm->tm_year / 10) * 10; + /* truncating to the decade? first year of the decade. + * must not be applied if year was truncated before! + */ + if (val != DTK_MILLENNIUM && val != DTK_CENTURY) + { + if (tm->tm_year > 0) + tm->tm_year = (tm->tm_year / 10) * 10; + else + tm->tm_year = - ((8-(tm->tm_year-1)) / 10) * 10; + } case DTK_YEAR: tm->tm_mon = 1; case DTK_QUARTER: @@ -2923,10 +2959,13 @@ interval_trunc(PG_FUNCTION_ARGS) switch (val) { case DTK_MILLENNIUM: + /* caution: C division may have negative remainder */ tm->tm_year = (tm->tm_year / 1000) * 1000; case DTK_CENTURY: + /* caution: C division may have negative remainder */ tm->tm_year = (tm->tm_year / 100) * 100; case DTK_DECADE: + /* caution: C division may have negative remainder */ tm->tm_year = (tm->tm_year / 10) * 10; case DTK_YEAR: tm->tm_mon = 0; @@ -3221,7 +3260,14 @@ timestamp_part(PG_FUNCTION_ARGS) break; case DTK_DECADE: - result = (tm->tm_year / 10); + /* what is a decade wrt dates? + * let us assume that decade 199 is 1990 thru 1999... + * decade 0 starts on year 1 BC, and -1 is 11 BC thru 2 BC... + */ + if (tm->tm_year>=0) + result = (tm->tm_year / 10); + else + result = -((8-(tm->tm_year-1)) / 10); break; case DTK_CENTURY: @@ -3232,7 +3278,7 @@ timestamp_part(PG_FUNCTION_ARGS) if (tm->tm_year > 0) result = ((tm->tm_year+99) / 100); else - /* caution: C division may yave negative remainder */ + /* caution: C division may have negative remainder */ result = - ((99 - (tm->tm_year-1))/100); break; @@ -3445,15 +3491,27 @@ timestamptz_part(PG_FUNCTION_ARGS) break; case DTK_DECADE: - result = (tm->tm_year / 10); + /* see comments in timestamp_part */ + if (tm->tm_year>0) + result = (tm->tm_year / 10); + else + result = - ((8-(tm->tm_year-1)) / 10); break; case DTK_CENTURY: - result = (tm->tm_year / 100); + /* see comments in timestamp_part */ + if (tm->tm_year > 0) + result = ((tm->tm_year+99) / 100); + else + result = - ((99 - (tm->tm_year-1))/100); break; case DTK_MILLENNIUM: - result = (tm->tm_year / 1000); + /* see comments in timestamp_part */ + if (tm->tm_year > 0) + result = ((tm->tm_year+999) / 1000); + else + result = - ((999 - (tm->tm_year-1))/1000); break; case DTK_JULIAN: @@ -3606,14 +3664,17 @@ interval_part(PG_FUNCTION_ARGS) break; case DTK_DECADE: + /* caution: C division may have negative remainder */ result = (tm->tm_year / 10); break; case DTK_CENTURY: + /* caution: C division may have negative remainder */ result = (tm->tm_year / 100); break; case DTK_MILLENNIUM: + /* caution: C division may have negative remainder */ result = (tm->tm_year / 1000); break; |