Add functions PERIOD_ADD and PERIOD_DIFF.

[Yury-Fridlyand]

Signed-off-by: Yury-Fridlyand [email protected]

Description

I referred to MySQL docs and tried to reproduce MySQL v.8.0.30 behavior as a reference.

New function: PERIOD_ADD.

Changes

Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM.

Fully compliant with MySQL.

Signature

updated LONG to INT

(INTEGER, INTEGER) -> INTEGER

Future changes (TODOs):

Update if and after #862

Notes

Not documented, but with experiments I discovered that

• 1 or 2 digits year is interpreted as 2000 + x.
• 2 digit year lower that 70 interpreted as 20xx, higher than 70 - as 19xx

Test queries:

SELECT PERIOD_ADD(200801, 2), PERIOD_ADD(200801, -12);
SELECT PERIOD_ADD(111, 2), PERIOD_ADD(1111, 2), PERIOD_ADD(1111, 2);
SELECT PERIOD_ADD(7011, 2), PERIOD_ADD(6911, 2);

New function: PERIOD_DIFF.

Changes

Returns the number of months between periods P1 and P2. P1 and P2 should be in the format YYMM or YYYYMM.

Fully compliant with MySQL.

Signature

updated LONG to INT

(INTEGER, INTEGER) -> INTEGER

Future changes (TODOs):

Update if and after #862

Notes

Not documented, but with experiments I discovered that

• 1 or 2 digits year is interpreted as 2000 + x.
• 2 digit year lower that 70 interpreted as 20xx, higher than 70 - as 19xx

Test queries:

SELECT PERIOD_DIFF(200802, 200703), PERIOD_DIFF(200802, 201003);
SELECT PERIOD_DIFF(7011, 6911);

Test data

I found that first 6 rows from date0, time0, time1, datetime0 are good for testing - these columns have different data types in MySQL. In OpenSearch SQL all [date][time] columns have timestamp type, so I use CAST for clear testing.

data

mysql> show fields from Calcs where field IN ('date0', 'time0', 'time1', 'datetime0');
+-----------+-----------+------+-----+---------+-------+
| Field     | Type      | Null | Key | Default | Extra |
+-----------+-----------+------+-----+---------+-------+
| date0     | date      | YES  |     | NULL    |       |
| time0     | datetime  | YES  |     | NULL    |       |
| time1     | time      | YES  |     | NULL    |       |
| datetime0 | timestamp | YES  |     | NULL    |       |
+-----------+-----------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> select date0, time0, time1, datetime0 from calcs;
+------------+---------------------+----------+---------------------+
| date0      | time0               | time1    | datetime0           |
+------------+---------------------+----------+---------------------+
| 2004-04-15 | 1899-12-30 21:07:32 | 19:36:22 | 2004-07-09 10:17:35 |
| 1972-07-04 | 1900-01-01 13:48:48 | 02:05:25 | 2004-07-26 12:30:34 |
| 1975-11-12 | 1900-01-01 18:21:08 | 09:33:31 | 2004-08-02 07:59:23 |
| 2004-06-04 | 1900-01-01 18:51:48 | 22:50:16 | 2004-07-05 13:14:20 |
| 2004-06-19 | 1900-01-01 15:01:19 | NULL     | 2004-07-28 23:30:22 |
| NULL       | 1900-01-01 08:59:39 | 19:57:33 | 2004-07-22 00:30:23 |
| NULL       | 1900-01-01 07:37:48 | NULL     | 2004-07-28 06:54:50 |
| NULL       | 1900-01-01 19:45:54 | 19:48:23 | 2004-07-12 17:30:16 |
| NULL       | 1900-01-01 09:00:59 | 22:20:14 | 2004-07-04 22:49:28 |
| NULL       | 1900-01-01 20:36:00 | NULL     | 2004-07-23 21:13:37 |
| NULL       | 1900-01-01 01:31:32 | 00:05:57 | 2004-07-14 08:16:44 |
| NULL       | 1899-12-30 22:15:40 | 04:40:49 | 2004-07-25 15:22:26 |
| NULL       | 1900-01-01 13:53:46 | 04:48:07 | 2004-07-17 14:01:56 |
| NULL       | 1900-01-01 04:57:51 | NULL     | 2004-07-19 22:21:31 |
| NULL       | 1899-12-30 22:42:43 | 18:58:41 | 2004-07-31 11:57:52 |
| NULL       | 1899-12-30 22:24:08 | NULL     | 2004-07-14 07:43:00 |
| NULL       | 1900-01-01 11:58:29 | 12:33:57 | 2004-07-28 12:34:28 |
+------------+---------------------+----------+---------------------+
17 rows in set (0.00 sec)

See team review in Bit-Quill#130

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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[Yury-Fridlyand]

Rebased to resolve conflicts.

[dai-chen]

Just minor comment on the function signature. Thanks for the changes!