Computed columns for mariadb fail with an extra NULL in the definition

General Discussion
1

I’m trying to add some computed columns to a table I have in MariaDB. I’m using the following definitions:

    - addColumn:
        columns:
        - column:
            name: type AS (SUBSTRING_INDEX(permission_id, ':', 1))
            computed: true
        - column:
            name: scope AS (SUBSTRING_INDEX(SUBSTRING_INDEX(permission_id, ':', -2), ':', 1))
            computed: true
        - column:
            name: access AS (SUBSTRING_INDEX(permission_id, ':', -1))
            computed: true
        tableName: Permission

This generates the following completely incorrect add:

ALTER TABLE main.Permission
    ADD `type AS (SUBSTRING_INDEX(permission_id, ':', 1))`                            NULL,
    ADD `scope AS (SUBSTRING_INDEX(SUBSTRING_INDEX(permission_id, ':', -2), ':', 1))` NULL,
    ADD `access AS (SUBSTRING_INDEX(permission_id, ':', -1))`                         NULL

It looks as though it’s completely ignoring the “computed” property for this database type. Is there another way to specify this or does liquibase simply not support adding virtual columns for MariaDB?

For reference the correct sql looks something like this:

ALTER TABLE main.Permission
    ADD type VARCHAR(50) AS (SUBSTRING_INDEX(permission_id, ':', 1)),
    ADD scope VARCHAR(50) AS (SUBSTRING_INDEX(SUBSTRING_INDEX(permission_id, ':', -2), ':', 1)),
    ADD access VARCHAR(50) AS (SUBSTRING_INDEX(permission_id, ':', -1))

I had to add the VARCHAR(50) myself. Initially I had that in my definitions above, but this caused a NullPointerException in Liquibase

2

It also fails to do this correctly for postgresql. The only one so far that seems to respect the computed property on addColumn is mssql. I dunno if I’ve typed something incorrectly or if it really is that computed is just ignored for these targets.