Comments - Generated (Virtual and Persistent/Stored) Columns

"Their value can be a not deterministic function, except if use in an index or a constraint."

In 10.1.6 (at least), you can use non-deterministic functions, but apparently the 252 character limitation still exists.

I'd show you, but I'm frustrated with the UI here. How did you get the <pre></pre> to work in your comment?

Let's try some <code>:

ALTER TABLE `z_test`
    ADD `Last_name_bit_length` INT(5)
        AS (BIT_LENGTH(`Name_Last`)) PERSISTENT
        AFTER `Name_Last`;

MariaDB [EcoReality]> SELECT Name_Last, Last_name_bit_length from z_test;
+------------+----------------------+
| Name_Last  | Last_name_bit_length |
+------------+----------------------+
| Bartfast   |                   64 |
| Flintstone |                   80 |
| Huston     |                   48 |
| Bah        |                   24 |
+------------+----------------------+
4 rows in set (0.00 sec)

Ah, that's better. :-)

(You guys REALLY need an "Edit" button...)