Add more tests for EXTRACT of date type

EXTRACT of date type is implemented as a wrapper around EXTRACT of
timestamp, so the code is already tested there.  But the externally
visible behavior of EXTRACT on date is not recorded anywhere.  Since
there is some discussion about reimplementing or refactoring some of
this, add some more explicit tests of EXTRACT on date, similar in
structure to existing EXTRACT tests on other data types.

Discussion: https://www.postgresql.org/message-id/flat/42b73d2d-da12-ba9f-570a-420e0cce19d9@phystech.edu

src/test/regress/expected/date.out

@@ -21,9 +21,10 @@ INSERT INTO DATE_TBL VALUES ('2000-04-03');
 INSERT INTO DATE_TBL VALUES ('2038-04-08');
 INSERT INTO DATE_TBL VALUES ('2039-04-09');
 INSERT INTO DATE_TBL VALUES ('2040-04-10');
-SELECT f1 AS "Fifteen" FROM DATE_TBL;
-  Fifteen   
-------------
+INSERT INTO DATE_TBL VALUES ('2040-04-10 BC');
+SELECT f1 FROM DATE_TBL;
+      f1       
+---------------
  04-09-1957
  06-13-1957
  02-28-1996
@@ -39,11 +40,12 @@ SELECT f1 AS "Fifteen" FROM DATE_TBL;
  04-08-2038
  04-09-2039
  04-10-2040
-(15 rows)
+ 04-10-2040 BC
+(16 rows)
 
-SELECT f1 AS "Nine" FROM DATE_TBL WHERE f1 < '2000-01-01';
-    Nine    
-------------
+SELECT f1 FROM DATE_TBL WHERE f1 < '2000-01-01';
+      f1       
+---------------
  04-09-1957
  06-13-1957
  02-28-1996
@@ -53,11 +55,12 @@ SELECT f1 AS "Nine" FROM DATE_TBL WHERE f1 < '2000-01-01';
  02-28-1997
  03-01-1997
  03-02-1997
-(9 rows)
+ 04-10-2040 BC
+(10 rows)
 
-SELECT f1 AS "Three" FROM DATE_TBL
+SELECT f1 FROM DATE_TBL
   WHERE f1 BETWEEN '2000-01-01' AND '2001-01-01';
-   Three    
+     f1     
 ------------
  04-01-2000
  04-02-2000
@@ -860,7 +863,8 @@ SELECT f1 - date '2000-01-01' AS "Days From 2K" FROM DATE_TBL;
         13977
         14343
         14710
-(15 rows)
+     -1475115
+(16 rows)
 
 SELECT f1 - date 'epoch' AS "Days From Epoch" FROM DATE_TBL;
  Days From Epoch 
@@ -880,7 +884,8 @@ SELECT f1 - date 'epoch' AS "Days From Epoch" FROM DATE_TBL;
            24934
            25300
            25667
-(15 rows)
+        -1464158
+(16 rows)
 
 SELECT date 'yesterday' - date 'today' AS "One day";
  One day 
@@ -920,6 +925,43 @@ SELECT date 'tomorrow' - date 'yesterday' AS "Two days";
 
 --
 -- test extract!
+--
+SELECT f1 as "date",
+    date_part('year', f1) AS year,
+    date_part('month', f1) AS month,
+    date_part('day', f1) AS day,
+    date_part('quarter', f1) AS quarter,
+    date_part('decade', f1) AS decade,
+    date_part('century', f1) AS century,
+    date_part('millennium', f1) AS millennium,
+    date_part('isoyear', f1) AS isoyear,
+    date_part('week', f1) AS week,
+    date_part('dow', f1) AS dow,
+    date_part('isodow', f1) AS isodow,
+    date_part('doy', f1) AS doy,
+    date_part('julian', f1) AS julian,
+    date_part('epoch', f1) AS epoch
+    FROM date_tbl;
+     date      | year  | month | day | quarter | decade | century | millennium | isoyear | week | dow | isodow | doy | julian  |     epoch     
+---------------+-------+-------+-----+---------+--------+---------+------------+---------+------+-----+--------+-----+---------+---------------
+ 04-09-1957    |  1957 |     4 |   9 |       2 |    195 |      20 |          2 |    1957 |   15 |   2 |      2 |  99 | 2435938 |    -401760000
+ 06-13-1957    |  1957 |     6 |  13 |       2 |    195 |      20 |          2 |    1957 |   24 |   4 |      4 | 164 | 2436003 |    -396144000
+ 02-28-1996    |  1996 |     2 |  28 |       1 |    199 |      20 |          2 |    1996 |    9 |   3 |      3 |  59 | 2450142 |     825465600
+ 02-29-1996    |  1996 |     2 |  29 |       1 |    199 |      20 |          2 |    1996 |    9 |   4 |      4 |  60 | 2450143 |     825552000
+ 03-01-1996    |  1996 |     3 |   1 |       1 |    199 |      20 |          2 |    1996 |    9 |   5 |      5 |  61 | 2450144 |     825638400
+ 03-02-1996    |  1996 |     3 |   2 |       1 |    199 |      20 |          2 |    1996 |    9 |   6 |      6 |  62 | 2450145 |     825724800
+ 02-28-1997    |  1997 |     2 |  28 |       1 |    199 |      20 |          2 |    1997 |    9 |   5 |      5 |  59 | 2450508 |     857088000
+ 03-01-1997    |  1997 |     3 |   1 |       1 |    199 |      20 |          2 |    1997 |    9 |   6 |      6 |  60 | 2450509 |     857174400
+ 03-02-1997    |  1997 |     3 |   2 |       1 |    199 |      20 |          2 |    1997 |    9 |   0 |      7 |  61 | 2450510 |     857260800
+ 04-01-2000    |  2000 |     4 |   1 |       2 |    200 |      20 |          2 |    2000 |   13 |   6 |      6 |  92 | 2451636 |     954547200
+ 04-02-2000    |  2000 |     4 |   2 |       2 |    200 |      20 |          2 |    2000 |   13 |   0 |      7 |  93 | 2451637 |     954633600
+ 04-03-2000    |  2000 |     4 |   3 |       2 |    200 |      20 |          2 |    2000 |   14 |   1 |      1 |  94 | 2451638 |     954720000
+ 04-08-2038    |  2038 |     4 |   8 |       2 |    203 |      21 |          3 |    2038 |   14 |   4 |      4 |  98 | 2465522 |    2154297600
+ 04-09-2039    |  2039 |     4 |   9 |       2 |    203 |      21 |          3 |    2039 |   14 |   6 |      6 |  99 | 2465888 |    2185920000
+ 04-10-2040    |  2040 |     4 |  10 |       2 |    204 |      21 |          3 |    2040 |   15 |   2 |      2 | 101 | 2466255 |    2217628800
+ 04-10-2040 BC | -2040 |     4 |  10 |       2 |   -204 |     -21 |         -3 |   -2040 |   15 |   1 |      1 | 100 |  976430 | -126503251200
+(16 rows)
+
 --
 -- epoch
 --
@@ -1111,6 +1153,132 @@ SELECT EXTRACT(CENTURY FROM TIMESTAMP '1970-03-20 04:30:00.00000'); -- 20
         20
 (1 row)
 
+--
+-- all possible fields
+--
+SELECT EXTRACT(MICROSECONDS  FROM DATE '2020-08-11');
+ date_part 
+-----------
+         0
+(1 row)
+
+SELECT EXTRACT(MILLISECONDS  FROM DATE '2020-08-11');
+ date_part 
+-----------
+         0
+(1 row)
+
+SELECT EXTRACT(SECOND        FROM DATE '2020-08-11');
+ date_part 
+-----------
+         0
+(1 row)
+
+SELECT EXTRACT(MINUTE        FROM DATE '2020-08-11');
+ date_part 
+-----------
+         0
+(1 row)
+
+SELECT EXTRACT(HOUR          FROM DATE '2020-08-11');
+ date_part 
+-----------
+         0
+(1 row)
+
+SELECT EXTRACT(DAY           FROM DATE '2020-08-11');
+ date_part 
+-----------
+        11
+(1 row)
+
+SELECT EXTRACT(MONTH         FROM DATE '2020-08-11');
+ date_part 
+-----------
+         8
+(1 row)
+
+SELECT EXTRACT(YEAR          FROM DATE '2020-08-11');
+ date_part 
+-----------
+      2020
+(1 row)
+
+SELECT EXTRACT(DECADE        FROM DATE '2020-08-11');
+ date_part 
+-----------
+       202
+(1 row)
+
+SELECT EXTRACT(CENTURY       FROM DATE '2020-08-11');
+ date_part 
+-----------
+        21
+(1 row)
+
+SELECT EXTRACT(MILLENNIUM    FROM DATE '2020-08-11');
+ date_part 
+-----------
+         3
+(1 row)
+
+SELECT EXTRACT(ISOYEAR       FROM DATE '2020-08-11');
+ date_part 
+-----------
+      2020
+(1 row)
+
+SELECT EXTRACT(QUARTER       FROM DATE '2020-08-11');
+ date_part 
+-----------
+         3
+(1 row)
+
+SELECT EXTRACT(WEEK          FROM DATE '2020-08-11');
+ date_part 
+-----------
+        33
+(1 row)
+
+SELECT EXTRACT(DOW           FROM DATE '2020-08-11');
+ date_part 
+-----------
+         2
+(1 row)
+
+SELECT EXTRACT(ISODOW        FROM DATE '2020-08-11');
+ date_part 
+-----------
+         2
+(1 row)
+
+SELECT EXTRACT(DOY           FROM DATE '2020-08-11');
+ date_part 
+-----------
+       224
+(1 row)
+
+SELECT EXTRACT(TIMEZONE      FROM DATE '2020-08-11');
+ERROR:  timestamp units "timezone" not supported
+CONTEXT:  SQL function "date_part" statement 1
+SELECT EXTRACT(TIMEZONE_M    FROM DATE '2020-08-11');
+ERROR:  timestamp units "timezone_m" not supported
+CONTEXT:  SQL function "date_part" statement 1
+SELECT EXTRACT(TIMEZONE_H    FROM DATE '2020-08-11');
+ERROR:  timestamp units "timezone_h" not supported
+CONTEXT:  SQL function "date_part" statement 1
+SELECT EXTRACT(EPOCH         FROM DATE '2020-08-11');
+ date_part  
+------------
+ 1597104000
+(1 row)
+
+SELECT EXTRACT(JULIAN        FROM DATE '2020-08-11');
+ date_part 
+-----------
+   2459073
+(1 row)
+
 --
 -- test trunc function!
 --

src/test/regress/expected/expressions.out

@@ -121,7 +121,7 @@ select count(*) from date_tbl
   where f1 not between '1997-01-01' and '1998-01-01';
  count 
 -------
-    12
+    13
 (1 row)
 
 explain (costs off)
@@ -155,6 +155,6 @@ select count(*) from date_tbl
   where f1 not between symmetric '1997-01-01' and '1998-01-01';
  count 
 -------
-    12
+    13
 (1 row)
 

src/test/regress/sql/date.sql

@@ -20,12 +20,13 @@ INSERT INTO DATE_TBL VALUES ('2000-04-03');
 INSERT INTO DATE_TBL VALUES ('2038-04-08');
 INSERT INTO DATE_TBL VALUES ('2039-04-09');
 INSERT INTO DATE_TBL VALUES ('2040-04-10');
+INSERT INTO DATE_TBL VALUES ('2040-04-10 BC');
 
-SELECT f1 AS "Fifteen" FROM DATE_TBL;
+SELECT f1 FROM DATE_TBL;
 
-SELECT f1 AS "Nine" FROM DATE_TBL WHERE f1 < '2000-01-01';
+SELECT f1 FROM DATE_TBL WHERE f1 < '2000-01-01';
 
-SELECT f1 AS "Three" FROM DATE_TBL
+SELECT f1 FROM DATE_TBL
   WHERE f1 BETWEEN '2000-01-01' AND '2001-01-01';
 
 --
@@ -218,6 +219,23 @@ SELECT date 'tomorrow' - date 'yesterday' AS "Two days";
 --
 -- test extract!
 --
+SELECT f1 as "date",
+    date_part('year', f1) AS year,
+    date_part('month', f1) AS month,
+    date_part('day', f1) AS day,
+    date_part('quarter', f1) AS quarter,
+    date_part('decade', f1) AS decade,
+    date_part('century', f1) AS century,
+    date_part('millennium', f1) AS millennium,
+    date_part('isoyear', f1) AS isoyear,
+    date_part('week', f1) AS week,
+    date_part('dow', f1) AS dow,
+    date_part('isodow', f1) AS isodow,
+    date_part('doy', f1) AS doy,
+    date_part('julian', f1) AS julian,
+    date_part('epoch', f1) AS epoch
+    FROM date_tbl;
+--
 -- epoch
 --
 SELECT EXTRACT(EPOCH FROM DATE        '1970-01-01');     --  0
@@ -264,6 +282,31 @@ SELECT EXTRACT(DECADE FROM DATE '0012-12-31 BC'); --  -2
 SELECT EXTRACT(CENTURY FROM NOW())>=21 AS True;       -- true
 SELECT EXTRACT(CENTURY FROM TIMESTAMP '1970-03-20 04:30:00.00000'); -- 20
 --
+-- all possible fields
+--
+SELECT EXTRACT(MICROSECONDS  FROM DATE '2020-08-11');
+SELECT EXTRACT(MILLISECONDS  FROM DATE '2020-08-11');
+SELECT EXTRACT(SECOND        FROM DATE '2020-08-11');
+SELECT EXTRACT(MINUTE        FROM DATE '2020-08-11');
+SELECT EXTRACT(HOUR          FROM DATE '2020-08-11');
+SELECT EXTRACT(DAY           FROM DATE '2020-08-11');
+SELECT EXTRACT(MONTH         FROM DATE '2020-08-11');
+SELECT EXTRACT(YEAR          FROM DATE '2020-08-11');
+SELECT EXTRACT(DECADE        FROM DATE '2020-08-11');
+SELECT EXTRACT(CENTURY       FROM DATE '2020-08-11');
+SELECT EXTRACT(MILLENNIUM    FROM DATE '2020-08-11');
+SELECT EXTRACT(ISOYEAR       FROM DATE '2020-08-11');
+SELECT EXTRACT(QUARTER       FROM DATE '2020-08-11');
+SELECT EXTRACT(WEEK          FROM DATE '2020-08-11');
+SELECT EXTRACT(DOW           FROM DATE '2020-08-11');
+SELECT EXTRACT(ISODOW        FROM DATE '2020-08-11');
+SELECT EXTRACT(DOY           FROM DATE '2020-08-11');
+SELECT EXTRACT(TIMEZONE      FROM DATE '2020-08-11');
+SELECT EXTRACT(TIMEZONE_M    FROM DATE '2020-08-11');
+SELECT EXTRACT(TIMEZONE_H    FROM DATE '2020-08-11');
+SELECT EXTRACT(EPOCH         FROM DATE '2020-08-11');
+SELECT EXTRACT(JULIAN        FROM DATE '2020-08-11');
+--
 -- test trunc function!
 --
 SELECT DATE_TRUNC('MILLENNIUM', TIMESTAMP '1970-03-20 04:30:00.00000'); -- 1001