parsing kafka messages using clickhouse kafka engine - clickhouse

Question

I am trying to consume kafka messages using CH kafka engine table, my messages structure:
{"after": {"created_at": "2023-01-15T14:54:34.981331Z", "col1": "xxxx", "col2": "xxx", "col3": "5812", "col4": "xxxx", "col5": "xxx"}}
as you can see it is a nested json {"after":{,,}} it follows this structure all the time
I tried the following Kafka engine schemas all of them resulted with empty rows:
A- Schema #1
CREATE TABLE db.table_queue ON CLUSTER clusterx(
col1 String,
col2 String,
col3 String,
col4 String,
col5 String,
created_at String
)
ENGINE = Kafka('xx:xx', 'topicxx’, 'groupxx’,
'JSONEachRow') settings kafka_thread_per_consumer = 0, kafka_num_consumers = 1;
B- Schema #2
CREATE TABLE db.table_queue ON CLUSTER clusterx(
after String
)
ENGINE = Kafka('xx:xx', 'topicxx’, 'groupxx’,
'JSONEachRow') settings kafka_thread_per_consumer = 0, kafka_num_consumers = 1;
when I tried a simpler messages with this structure:
{"col": "test7"}
{"col": "test8"}
{"col": "test9"}
{"col": "test10"}
{"col": "test11"}
{"col": "test12"}
I managed to consume them with success with the following table definition:
CREATE TABLE db.table_queue ON CLUSTER clusterx(
col String
)
ENGINE = Kafka('xx:xx', 'topicxx’, 'groupxx’,
'JSONEachRow') settings kafka_thread_per_consumer = 0, kafka_num_consumers = 1;