Fix a bug in input processing for the "interval" type. Previously,

"microsecond" and "millisecond" units were not considered valid input
by themselves, which caused inputs like "1 millisecond" to be rejected
erroneously.

Update the docs, add regression tests, and backport to 8.2 and 8.1

Author: Neil Conway

doc/src/sgml/datatype.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.201 2007/05/21 17:10:28 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.202 2007/05/29 04:58:43 neilc Exp $ -->
 
  <chapter id="datatype">
   <title id="datatype-title">Data Types</title>
@@ -1880,7 +1880,8 @@ January 8 04:05:06 1999 PST
 </programlisting>
 
       Where: <replaceable>quantity</> is a number (possibly signed);
-      <replaceable>unit</> is <literal>second</literal>,
+      <replaceable>unit</> is <literal>microsecond</literal>,
+      <literal>millisecond</literal>, <literal>second</literal>,
       <literal>minute</literal>, <literal>hour</literal>, <literal>day</literal>,
       <literal>week</literal>, <literal>month</literal>, <literal>year</literal>,
       <literal>decade</literal>, <literal>century</literal>, <literal>millennium</literal>,

src/backend/utils/adt/datetime.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.179 2007/05/27 20:32:16 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.180 2007/05/29 04:58:43 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -924,6 +924,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
 #else
 								*fsec = frac;
 #endif
+								tmask = DTK_ALL_SECS_M;
 							}
 							break;
 
@@ -1699,6 +1700,7 @@ DecodeTimeOnly(char **field, int *ftype, int nf,
 #else
 								*fsec = frac;
 #endif
+								tmask = DTK_ALL_SECS_M;
 							}
 							break;
 
@@ -2805,6 +2807,7 @@ DecodeInterval(char **field, int *ftype, int nf, int *dtype, struct pg_tm * tm,
 #else
 						*fsec += (val + fval) * 1e-6;
 #endif
+						tmask = DTK_M(MICROSECOND);
 						break;
 
 					case DTK_MILLISEC:
@@ -2813,6 +2816,7 @@ DecodeInterval(char **field, int *ftype, int nf, int *dtype, struct pg_tm * tm,
 #else
 						*fsec += (val + fval) * 1e-3;
 #endif
+						tmask = DTK_M(MILLISECOND);
 						break;
 
 					case DTK_SECOND:
@@ -2822,7 +2826,15 @@ DecodeInterval(char **field, int *ftype, int nf, int *dtype, struct pg_tm * tm,
 #else
 						*fsec += fval;
 #endif
-						tmask = DTK_M(SECOND);
+						/*
+						 * If any subseconds were specified, consider
+						 * this microsecond and millisecond input as
+						 * well.
+						 */
+						if (fval == 0)
+							tmask = DTK_M(SECOND);
+						else
+							tmask = DTK_ALL_SECS_M;
 						break;
 
 					case DTK_MINUTE:

src/include/utils/datetime.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/datetime.h,v 1.65 2007/02/19 17:41:39 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/datetime.h,v 1.66 2007/05/29 04:58:43 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -100,17 +100,19 @@
 #define HOUR	10
 #define MINUTE	11
 #define SECOND	12
-#define DOY		13
-#define DOW		14
-#define UNITS	15
-#define ADBC	16
+#define MILLISECOND 13
+#define MICROSECOND 14
+#define DOY		15
+#define DOW		16
+#define UNITS	17
+#define ADBC	18
 /* these are only for relative dates */
-#define AGO		17
-#define ABS_BEFORE		18
-#define ABS_AFTER		19
+#define AGO		19
+#define ABS_BEFORE		20
+#define ABS_AFTER		21
 /* generic fields to help with parsing */
-#define ISODATE 20
-#define ISOTIME 21
+#define ISODATE 22
+#define ISOTIME 23
 /* reserved for unrecognized string values */
 #define UNKNOWN_FIELD	31
 
@@ -175,8 +177,10 @@
 
 #define DTK_M(t)		(0x01 << (t))
 
+/* Convenvience: a second, plus any fractional component */
+#define DTK_ALL_SECS_M	(DTK_M(SECOND) | DTK_M(MILLISECOND) | DTK_M(MICROSECOND))
 #define DTK_DATE_M		(DTK_M(YEAR) | DTK_M(MONTH) | DTK_M(DAY))
-#define DTK_TIME_M		(DTK_M(HOUR) | DTK_M(MINUTE) | DTK_M(SECOND))
+#define DTK_TIME_M		(DTK_M(HOUR) | DTK_M(MINUTE) | DTK_ALL_SECS_M)
 
 #define MAXDATELEN		63		/* maximum possible length of an input date
 								 * string (not counting tr. null) */

src/test/regress/expected/interval.out

@@ -326,3 +326,26 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
  @ 29 days 23 hours
 (1 row)
 
+-- test fractional second input, and detection of duplicate units
+SET DATESTYLE = 'ISO';
+SELECT '1 millisecond'::interval, '1 microsecond'::interval,
+       '500 seconds 99 milliseconds 51 microseconds'::interval;
+   interval   |    interval     |    interval     
+--------------+-----------------+-----------------
+ 00:00:00.001 | 00:00:00.000001 | 00:08:20.099051
+(1 row)
+
+SELECT '3 days 5 milliseconds'::interval;
+      interval       
+---------------------
+ 3 days 00:00:00.005
+(1 row)
+
+SELECT '1 second 2 seconds'::interval;              -- error
+ERROR:  invalid input syntax for type interval: "1 second 2 seconds"
+SELECT '10 milliseconds 20 milliseconds'::interval; -- error
+ERROR:  invalid input syntax for type interval: "10 milliseconds 20 milliseconds"
+SELECT '5.5 seconds 3 milliseconds'::interval;      -- error
+ERROR:  invalid input syntax for type interval: "5.5 seconds 3 milliseconds"
+SELECT '1:20:05 5 microseconds'::interval;          -- error
+ERROR:  invalid input syntax for type interval: "1:20:05 5 microseconds"

src/test/regress/sql/interval.sql

@@ -116,3 +116,14 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 -- test justify_interval()
 
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
+
+-- test fractional second input, and detection of duplicate units
+SET DATESTYLE = 'ISO';
+SELECT '1 millisecond'::interval, '1 microsecond'::interval,
+       '500 seconds 99 milliseconds 51 microseconds'::interval;
+SELECT '3 days 5 milliseconds'::interval;
+
+SELECT '1 second 2 seconds'::interval;              -- error
+SELECT '10 milliseconds 20 milliseconds'::interval; -- error
+SELECT '5.5 seconds 3 milliseconds'::interval;      -- error
+SELECT '1:20:05 5 microseconds'::interval;          -- error