The now() function in mappings

You can use the now() function in mappings.

In the Kafka topic mapping, you can use the now()function. It returns TIMEUUID, which is documented in the UUID and timeuuid column.

For example:

"topic.my_topic.my_ks.my_table.mapping": "col1=now()"

In this example, you must create col1 in a CQL table with the following definition:

col1 timeuuid

You can use the now() function for mapping of multiple database columns:

"topic.my_topic.my_ks.my_table.mapping": "col1=now(), col2=now(), col3=now()"

In the example above, each occurrence of now() is evaluated and return a different TIMEUUID.

Behavior of now() with DELETE records

When the value of a record arrives to DataStax Apache Kafka Connector instance, it could be a DELETE, assuming deletesEnabled is true; see Kafka topic-to-table settings. For example, consider a case where a user has mapping and used the now() function:

my_pk=value.my_pk, my_value=value.my_value, loaded_at=now()

If there is an insertion of a value that is null, such as:

"{\"my_pk\": 1234567, \"my_value\": null}";

In this scenario, the called now() function is ignored, and the record is deleted.