* fix timestamp default value bug in multiple time zones.

[crazycs520]

What problem does this PR solve?

Fix timestamp default value bug in multiple time zones.
TiDB

mysql> set @@time_zone="+08:00"
mysql> create table t1 (a int, b timestamp default "2019-01-17 14:46:14"); 
mysql> insert into t1 set a=1; /* b = "2019-01-17 14:46:14 +08:00" = "2019-01-17 06:46:14 UTC"   */
mysql> show create table t1
+-------+-------------------------------------------------------------+
| Table | Create Table                                                |
+-------+-------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (                                         |
|       |   `a` int(11) DEFAULT NULL,                                 |
|       |   `b` timestamp DEFAULT '2019-01-17 14:46:14'               |
|       | ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+-------------------------------------------------------------+
mysql> set @@time_zone="+00:00"
mysql> insert into t1 set a=2;  /* b = "2019-01-17 14:46:14 +00:00" = "2019-01-17 14:46:14 UTC"   */
mysql> show create table t1
+-------+-------------------------------------------------------------+
| Table | Create Table                                                |
+-------+-------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (                                         |
|       |   `a` int(11) DEFAULT NULL,                                 |
|       |   `b` timestamp DEFAULT '2019-01-17 14:46:14'               |
|       | ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+-------------------------------------------------------------+
mysql> select a,b from t1;
+---+---------------------+
| a | b                   |
+---+---------------------+
| 1 | 2019-01-17 06:46:14 |
| 2 | 2019-01-17 14:46:14 |
+---+---------------------+
2 rows in set
mysql> set @@time_zone="+08:00"
mysql> select a,b from t1;
+---+---------------------+
| a | b                   |
+---+---------------------+
| 1 | 2019-01-17 14:46:14 |
| 2 | 2019-01-17 22:46:14 |
+---+---------------------+

mysql

mysql> set @@time_zone="+08:00"
mysql> create table t1 (a int, b timestamp default "2019-01-17 14:46:14");
mysql> insert into t1 set a=1
mysql> show create table t1
+-------+--------------------------------------------------------+
| Table | Create Table                                           |
+-------+--------------------------------------------------------+
| t1    | CREATE TABLE `t1` (                                    |
|       |   `a` int(11) DEFAULT NULL,                            |
|       |   `b` timestamp NOT NULL DEFAULT '2019-01-17 14:46:14' | 
|       | ) ENGINE=InnoDB DEFAULT CHARSET=latin1                 |
+-------+--------------------------------------------------------+
mysql> set @@time_zone="+00:00"
mysql> insert into t1 set a=2;
mysql> show create table t1
+-------+--------------------------------------------------------+
| Table | Create Table                                           |
+-------+--------------------------------------------------------+
| t1    | CREATE TABLE `t1` (                                    |
|       |   `a` int(11) DEFAULT NULL,                            |
|       |   `b` timestamp NOT NULL DEFAULT '2019-01-17 06:46:14' |
|       | ) ENGINE=InnoDB DEFAULT CHARSET=latin1                 |
+-------+--------------------------------------------------------+
mysql> select a,b from t1;
+---+---------------------+
| a | b                   |
+---+---------------------+
| 1 | 2019-01-17 06:46:14 |
| 2 | 2019-01-17 06:46:14 |
+---+---------------------+
2 rows in set
mysql> set @@time_zone="+08:00"
mysql> select a,b from t1;
+---+---------------------+
| a | b                   |
+---+---------------------+
| 1 | 2019-01-17 14:46:14 |
| 2 | 2019-01-17 14:46:14 |
+---+---------------------+

Related Parser PR:pingcap/parser#183
releated Issue: #9064

What is changed and how it works?

Old tidb save timestamp default value without convert to UTC time. Then if TiDB in multiple timezone, and use the default value of timestamp will have different result problem.
This PR will save timestamp default value in UTC time.
And add a version field to solve compatible problem.

Check List

Tests

• Unit test

Code changes

• Has exported function/method change

Side effects

Related changes

• Need to cherry-pick to the release branch

[crazycs520]

/run-all-tests

[crazycs520]

/run-all-tests

[crazycs520]

/run-all-tests

[crazycs520]

/run-all-tests

[crazycs520]

@zimulala @XuHuaiyu @winkyao PTAL, Ci failed because go.mod. After parser merged, I will fix this.

[winkyao]

reset LGTM

[crazycs520]

/run-all-tests

[crazycs520]

@XuHuaiyu PTAL

[crazycs520]

/run-all-tests

[ciscoxll]

LGTM

[crazycs520]

/run-all-tests

[zz-jason]

@crazycs520 Is this PR ready to be merged?