Accept an INTERVAL argument for SET TIME ZONE per SQL99.

 Modified the parser and the SET handlers to use full Node structures
 rather than simply a character string argument.
Implement INTERVAL() YEAR TO MONTH (etc) syntax per SQL99.
 Does not yet accept the goofy string format that goes along with, but
 this should be fairly straight forward to fix now as a bug or later
 as a feature.
Implement precision for the INTERVAL() type.
 Use the typmod mechanism for both of INTERVAL features.
Fix the INTERVAL syntax in the parser:
 opt_interval was in the wrong place.
INTERVAL is now a reserved word, otherwise we get reduce/reduce errors.
Implement an explicit date_part() function for TIMETZ.
 Should fix coersion problem with INTERVAL reported by Peter E.
Fix up some error messages for date/time types.
 Use all caps for type names within message.
Fix recently introduced side-effect bug disabling 'epoch' as a recognized
 field for date_part() etc. Reported by Peter E. (??)
Bump catalog version number.
Rename "microseconds" current transaction time field
 from ...Msec to ...Usec. Duh!
date/time regression tests updated for reference platform, but a few
 changes will be necessary for others.

1 files changed, 112 insertions, 1 deletions

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index f8693c753af..d59d9f9e117 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/date.c,v 1.61 2001/10/04 15:14:22 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/date.c,v 1.62 2001/10/18 17:30:15 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1458,6 +1458,117 @@ text_timetz(PG_FUNCTION_ARGS)
 							   Int32GetDatum(-1));
 }
 
+/* timetz_part()
+ * Extract specified field from time type.
+ */
+Datum
+timetz_part(PG_FUNCTION_ARGS)
+{
+	text	   *units = PG_GETARG_TEXT_P(0);
+	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
+	float8		result;
+	int			type,
+				val;
+	int			i;
+	char	   *up,
+			   *lp,
+				lowunits[MAXDATELEN + 1];
+
+	if (VARSIZE(units) - VARHDRSZ > MAXDATELEN)
+		elog(ERROR, "TIMETZ units '%s' not recognized",
+			 DatumGetCString(DirectFunctionCall1(textout,
+												 PointerGetDatum(units))));
+	up = VARDATA(units);
+	lp = lowunits;
+	for (i = 0; i < (VARSIZE(units) - VARHDRSZ); i++)
+		*lp++ = tolower((unsigned char) *up++);
+	*lp = '\0';
+
+	type = DecodeUnits(0, lowunits, &val);
+	if (type == UNKNOWN_FIELD)
+		type = DecodeSpecial(0, lowunits, &val);
+
+	if (type == UNITS)
+	{
+		double		trem;
+		double		dummy;
+		int			tz;
+		double		fsec;
+		struct tm	tt,
+				   *tm = &tt;
+
+		trem = time->time;
+		TMODULO(trem, tm->tm_hour, 3600e0);
+		TMODULO(trem, tm->tm_min, 60e0);
+		TMODULO(trem, tm->tm_sec, 1e0);
+		fsec = trem;
+		tz = time->zone;
+
+		switch (val)
+		{
+			case DTK_TZ:
+				result = tz;
+				break;
+
+			case DTK_TZ_MINUTE:
+				result = tz / 60;
+				TMODULO(result, dummy, 60e0);
+				break;
+
+			case DTK_TZ_HOUR:
+				dummy = tz;
+				TMODULO(dummy, result, 3600e0);
+				break;
+
+			case DTK_MICROSEC:
+				result = ((tm->tm_sec + fsec) * 1000000);
+				break;
+
+			case DTK_MILLISEC:
+				result = ((tm->tm_sec + fsec) * 1000);
+				break;
+
+			case DTK_SECOND:
+				result = (tm->tm_sec + fsec);
+				break;
+
+			case DTK_MINUTE:
+				result = tm->tm_min;
+				break;
+
+			case DTK_HOUR:
+				result = tm->tm_hour;
+				break;
+
+			case DTK_DAY:
+			case DTK_MONTH:
+			case DTK_QUARTER:
+			case DTK_YEAR:
+			case DTK_DECADE:
+			case DTK_CENTURY:
+			case DTK_MILLENNIUM:
+			default:
+				elog(ERROR, "TIMETZ units '%s' not supported",
+					 DatumGetCString(DirectFunctionCall1(textout,
+														 PointerGetDatum(units))));
+				result = 0;
+		}
+	}
+	else if ((type == RESERV) && (val == DTK_EPOCH))
+	{
+		result = time->time - time->zone;
+	}
+	else
+	{
+		elog(ERROR, "TIMETZ units '%s' not recognized",
+			 DatumGetCString(DirectFunctionCall1(textout,
+												 PointerGetDatum(units))));
+		result = 0;
+	}
+
+	PG_RETURN_FLOAT8(result);
+}
+
 /* timetz_zone()
  * Encode time with time zone type with specified time zone.
  */