Re: Issues setting a default value/expression in a MySQL table

[Rick James]

MySQL 5.6.4 and MariaDB 5.3 introduced Microsecond support.

Why did you want that lengthy expression instead of
RIGHT(NOW(3), 3)

mysql> SELECT NOW(3), RIGHT(NOW(3), 3);
+-------------------------+------------------+
| NOW(3)                  | RIGHT(NOW(3), 3) |
+-------------------------+------------------+
| 2016-10-16 15:34:31.266 | 266              |
+-------------------------+------------------+

However you might need

RIGHT(NOW(3), 3) + 0

to make it numeric.