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

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5dd95d73a1af83d26a4c5e5c4122db4335e1a92c..749360a4b713279dd703ff9c8d4737b7a1c378fb 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10432,12 +10432,16 @@ SELECT EXTRACT(MONTH FROM INTERVAL '2 years 13 months');
       quarter
       
        
-        The quarter of the year (1–4) that the date is in
+        The quarter of the year (1–4) that the date is in;
+        for interval values, the month field divided by 3
+        plus 1
        
 
 
 SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40');
 Result: 1
+SELECT EXTRACT(QUARTER FROM INTERVAL '1 year 6 months');
+Result: 3
 
       
      
@@ -10508,9 +10512,16 @@ SELECT EXTRACT(SECOND FROM TIME '17:12:28.5');
         week to get consistent results.
        
 
+       
+        For interval values, the week field is simply the number
+        of integral days divided by 7.
+       
+
 
 SELECT EXTRACT(WEEK FROM TIMESTAMP '2001-02-16 20:38:40');
 Result: 7
+SELECT EXTRACT(WEEK FROM INTERVAL '13 days 24 hours');
+Result: 1
 
       
      

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 43800addf48bc321b0e84d5a94bf31a5c362831d..db9eea90982fd6e1db4accf691608946873c51e2 100644 (file)
--- 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:

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 51ae010c7baba4cb66d65831851c8bcbcb12482c..e5d919d0cf025e4d8963f8730b51bd3c6512f8f1 100644 (file)
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1834,6 +1834,7 @@ SELECT f1,
     EXTRACT(MINUTE FROM f1) AS MINUTE,
     EXTRACT(HOUR FROM f1) AS HOUR,
     EXTRACT(DAY FROM f1) AS DAY,
+    EXTRACT(WEEK FROM f1) AS WEEK,
     EXTRACT(MONTH FROM f1) AS MONTH,
     EXTRACT(QUARTER FROM f1) AS QUARTER,
     EXTRACT(YEAR FROM f1) AS YEAR,
@@ -1842,20 +1843,52 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
- infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
- -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | week | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |    1 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |    0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |    0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |    0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |    0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |    0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |      |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |      |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
+
+SELECT -f1,
+    EXTRACT(MICROSECOND FROM -f1) AS MICROSECOND,
+    EXTRACT(MILLISECOND FROM -f1) AS MILLISECOND,
+    EXTRACT(SECOND FROM -f1) AS SECOND,
+    EXTRACT(MINUTE FROM -f1) AS MINUTE,
+    EXTRACT(HOUR FROM -f1) AS HOUR,
+    EXTRACT(DAY FROM -f1) AS DAY,
+    EXTRACT(WEEK FROM -f1) AS WEEK,
+    EXTRACT(MONTH FROM -f1) AS MONTH,
+    EXTRACT(QUARTER FROM -f1) AS QUARTER,
+    EXTRACT(YEAR FROM -f1) AS YEAR,
+    EXTRACT(DECADE FROM -f1) AS DECADE,
+    EXTRACT(CENTURY FROM -f1) AS CENTURY,
+    EXTRACT(MILLENNIUM FROM -f1) AS MILLENNIUM,
+    EXTRACT(EPOCH FROM -f1) AS EPOCH
+    FROM INTERVAL_TBL;
+             ?column?              | microsecond | millisecond |  second   | minute |   hour    |    day    | week | month | quarter |   year    |  decade   |  century  | millennium |       epoch        
+-----------------------------------+-------------+-------------+-----------+--------+-----------+-----------+------+-------+---------+-----------+-----------+-----------+------------+--------------------
+ @ 1 min ago                       |           0 |       0.000 |  0.000000 |     -1 |         0 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |         -60.000000
+ @ 5 hours ago                     |           0 |       0.000 |  0.000000 |      0 |        -5 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |      -18000.000000
+ @ 10 days ago                     |           0 |       0.000 |  0.000000 |      0 |         0 |       -10 |   -1 |     0 |       1 |         0 |         0 |         0 |          0 |     -864000.000000
+ @ 34 years ago                    |           0 |       0.000 |  0.000000 |      0 |         0 |         0 |    0 |     0 |      -1 |       -34 |        -3 |         0 |          0 | -1072958400.000000
+ @ 3 mons ago                      |           0 |       0.000 |  0.000000 |      0 |         0 |         0 |    0 |    -3 |      -2 |         0 |         0 |         0 |          0 |    -7776000.000000
+ @ 14 secs                         |    14000000 |   14000.000 | 14.000000 |      0 |         0 |         0 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |          14.000000
+ @ 1 day 2 hours 3 mins 4 secs ago |    -4000000 |   -4000.000 | -4.000000 |     -3 |        -2 |        -1 |    0 |     0 |       1 |         0 |         0 |         0 |          0 |      -93784.000000
+ @ 6 years ago                     |           0 |       0.000 |  0.000000 |      0 |         0 |         0 |    0 |     0 |      -1 |        -6 |         0 |         0 |          0 |  -189345600.000000
+ @ 5 mons ago                      |           0 |       0.000 |  0.000000 |      0 |         0 |         0 |    0 |    -5 |      -2 |         0 |         0 |         0 |          0 |   -12960000.000000
+ @ 5 mons 12 hours ago             |           0 |       0.000 |  0.000000 |      0 |       -12 |         0 |    0 |    -5 |      -2 |         0 |         0 |         0 |          0 |   -13003200.000000
+ -infinity                         |             |             |           |        | -Infinity | -Infinity |      |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |          -Infinity
+ infinity                          |             |             |           |        |  Infinity |  Infinity |      |       |         |  Infinity |  Infinity |  Infinity |   Infinity |           Infinity
 (12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error

diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index fbf6e064d66bde02d700a2f8c665ba88eea0745e..55054ae65d16f44fddb6d486c1f4c9665d0a647f 100644 (file)
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -592,6 +592,7 @@ SELECT f1,
     EXTRACT(MINUTE FROM f1) AS MINUTE,
     EXTRACT(HOUR FROM f1) AS HOUR,
     EXTRACT(DAY FROM f1) AS DAY,
+    EXTRACT(WEEK FROM f1) AS WEEK,
     EXTRACT(MONTH FROM f1) AS MONTH,
     EXTRACT(QUARTER FROM f1) AS QUARTER,
     EXTRACT(YEAR FROM f1) AS YEAR,
@@ -601,6 +602,23 @@ SELECT f1,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
 
+SELECT -f1,
+    EXTRACT(MICROSECOND FROM -f1) AS MICROSECOND,
+    EXTRACT(MILLISECOND FROM -f1) AS MILLISECOND,
+    EXTRACT(SECOND FROM -f1) AS SECOND,
+    EXTRACT(MINUTE FROM -f1) AS MINUTE,
+    EXTRACT(HOUR FROM -f1) AS HOUR,
+    EXTRACT(DAY FROM -f1) AS DAY,
+    EXTRACT(WEEK FROM -f1) AS WEEK,
+    EXTRACT(MONTH FROM -f1) AS MONTH,
+    EXTRACT(QUARTER FROM -f1) AS QUARTER,
+    EXTRACT(YEAR FROM -f1) AS YEAR,
+    EXTRACT(DECADE FROM -f1) AS DECADE,
+    EXTRACT(CENTURY FROM -f1) AS CENTURY,
+    EXTRACT(MILLENNIUM FROM -f1) AS MILLENNIUM,
+    EXTRACT(EPOCH FROM -f1) AS EPOCH
+    FROM INTERVAL_TBL;
+
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 SELECT EXTRACT(TIMEZONE FROM INTERVAL '2 days');  -- error