Magento 2.3.0: How to add TIMESTAMP_INIT as a default value in declarative schema?

Question

As I'm adding CURRENT_TIMESTAMP as a default value for created_datetime and updated_datetime columns in my database table named faqs, I'm getting both the columns updated while edit the FAQ in admin form.

I want to update timestamp only for updated_datetime column. So for that I'm trying to add TIMESTAMP_INIT as a default value for created_datetime column and TIMESTAMP_INIT_UPDATE for updated_datetime column as described follows:

app\code\Namespace\Module\etc\db_schema.xml

<schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Setup/Declaration/Schema/etc/schema.xsd">
    <table name="faqs" resource="default" engine="innodb" comment="FAQ Table">
        ........
        <column xsi:type="timestamp" name="created_datetime" nullable="false" default="TIMESTAMP_INIT" comment="Created Datetime"/>
        <column xsi:type="timestamp" name="updated_datetime" nullable="false" default="TIMESTAMP_INIT_UPDATE" comment="Updated Datetime"/>
        ........
    </table>
</schema>

While running php bin/magento setup:upgrade command in cmd, I'm getting following error:

Element 'column', attribute 'default': [facet 'enumeration'] The value 'TIMESTAMP_INIT' is not an element of the set {'CURRENT_TIMESTAMP', '0', 'NULL'}.
Line: 12
Element 'column', attribute 'default': 'TIMESTAMP_INIT' is not a valid value of the atomic type 'defaults'.
Line: 12
Element 'column', attribute 'default': [facet 'enumeration'] The value 'TIMESTAMP_INIT_UPDATE' is not an element of the set {'CURRENT_TIMESTAMP', '0', 'NULL'}.
Line: 13
Element 'column', attribute 'default': 'TIMESTAMP_INIT_UPDATE' is not a valid value of the atomic type 'defaults'.
Line: 13

Can anyone please help me to correct the syntax or guide me how to achieve this in db_schema.xml? Thanks in anticipation.

Answer 1

You have to need update created_datetime and updated_datetime with on_update="false" and on_update="true" in db_schema.xml

app\code\Namespace\Module\etc\db_schema.xml

<column xsi:type="timestamp" name="created_datetime" nullable="false" default="CURRENT_TIMESTAMP" on_update="false" comment="Created Datetime"/>
<column xsi:type="timestamp" name="updated_datetime" nullable="false" default="CURRENT_TIMESTAMP" on_update="true" comment="Updated Datetime"/>

Hope it help!