Created at and Updated at columns using db schema xml - Magento 2

Question

I have a custom table. Using the InstallSchema, I was able to add default values using:

)->addColumn(
    'created_at',
    \Magento\Framework\DB\Ddl\Table::TYPE_TIMESTAMP,
    null,
    ['nullable' => false, 'default' => \Magento\Framework\DB\Ddl\Table::TIMESTAMP_INIT],
    'Created At'
)->addColumn(
    'updated_at',
    \Magento\Framework\DB\Ddl\Table::TYPE_TIMESTAMP,
    null,
    ['nullable' => false, 'default' => \Magento\Framework\DB\Ddl\Table::TIMESTAMP_INIT_UPDATE],
    'Updated At'

How can i achieve the same thing using the db schema xml file? :

<table comment="my table comment" engine="innodb" name="my_table_name" resource="default">
    ......
    <column name="created_at" nullable="false" xsi:type="datetime"/>
    <column name="updated_at" nullable="true" xsi:type="datetime"/>
</table>

Answer 1

Eventually, I found out. Please see:

<column name="created_at" nullable="false" xsi:type="datetime" default="CURRENT_TIMESTAMP" on_update="false"/>
<column name="updated_at" nullable="true" xsi:type="datetime" default="CURRENT_TIMESTAMP" on_update="true"/>

I needed to add this part: default="CURRENT_TIMESTAMP"

Answer 2

<table comment="my table comment" engine="innodb" name="my_table_name" resource="default">
    <column xsi:type="timestamp" name="created_at" on_update="false" nullable="false" default="CURRENT_TIMESTAMP" comment="Created At"/>
    <column xsi:type="timestamp" name="updated_at" on_update="true" nullable="false" default="CURRENT_TIMESTAMP" comment="Updated At"/>
</table>  

Use xsi:type="timestamp". Please implement and let me know if it is helpful.