Add String to Array, without creating a new row in Clickhouse table - python-3.x

Question

I just started to study the clickhouse! I use python and library clickhouse_connect. Can't get to add a new string to the Array(String)
I try to create new String to Array
My code:
import clickhouse_connect
ch_client = clickhouse_connect.get_client(host=ch_host, user=ch_user, password=ch_pass, database=ch_datebase)
ch_client.command(f'CREATE TABLE IF NOT EXISTS {ch_table} (key String, strings Array(String)) ENGINE MergeTree ORDER BY key')
insert_data = [['123', ['string1']]]
ch_client.insert(ch_table, insert_data, column_names=['key', 'strings'])
insert_data = [['123', ['string2']]]
ch_client.insert(ch_table, insert_data, column_names=['key', 'strings'])
Is there an easy way to insert a new row into the list if there is already such a key, and if there is no such key, then create a new row?

Answer 1

You could just insert your rows, then write a query that gives you what you want:
SELECT
key,
groupArrayArray(strings)
FROM ch_table
GROUP BY key;
If that works, you could create a materialized view from this query:
CREATE MATERIALIZED VIEW ch_table_view
ENGINE = AggregatingMergeTree
ORDER BY key
POPULATE AS
SELECT
key,
groupArrayArrayState(strings) AS strings_merged
FROM ch_table
GROUP BY key;
Notice the -State aggregate combinator was used, which keeps a "running total" of the array of strings. To read this column, you need to use the corresponding -Merge combinator:
SELECT
key,
groupArrayArrayMerge(strings_merged)
FROM ch_table_view
GROUP BY key;