Add MySQL8Dialect and MySQL8InnoDBDialect

[dennis-gr]

MySQL 8 is deprecating integer display widths, see here and here for more information.

The MySQL8Dialect uses BOOLEAN instead of TINYINT(1) for DbType.Boolean.

[fredericDelaporte]

Thanks for your contribution. It seems to me it misses the point you were willing to address, display width being deprecated for integers types.

[dennis-gr]

No, it actually needs to be BOOLEAN since TINYINT(1) is treated differently by connectors. Because of this, TINYINT(1) is probably the only case where specifiying the display width is/was actually useful.

You can verify this yourself:

mysql> create table a (b TINYINT(1));
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+------------------------------------------------------------------------------+
| Level   | Code | Message                                                                      |
+---------+------+------------------------------------------------------------------------------+
| Warning | 1681 | Integer display width is deprecated and will be removed in a future release. |
+---------+------+------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> create table b (c BOOLEAN);
Query OK, 0 rows affected (0.00 sec)

mysql> show warnings;
Empty set (0.00 sec)

[fredericDelaporte]

According to your link, the connector documentation tell to use BOOL. It do not seem to tell anything about BOOLEAN. So, should the mapping use BOOL instead, just in case?

[dennis-gr]

Since the official MySQL documentation specifies that both BOOL and BOOLEAN are valid, I think it's fine to leave it as is.