Controlling string unescaping in Clickhouse? - clickhouse

Question

I am trying to load JSON data from Kafka into Clickhouse where the JSON contains some escape sequences. E.g:
:) SELECT JSONExtractRaw('{"message": "Hello \"to\" you!"}', 'message')
SELECT JSONExtractRaw('{"message": "Hello "to" you!"}', 'message')
┌─JSONExtractRaw('{"message": "Hello "to" you!"}', 'message')─┐
│ "Hello " │
└─────────────────────────────────────────────────────────────┘
It appears that prior to calling JSONExtractRaw, the input strings are unescaped, which produces invalid JSON. The unescaping seems to be reproducible with this minimal example:
:) SELECT 'Hello \"there\"'
SELECT 'Hello "there"'
┌─'Hello "there"'─┐
│ Hello "there" │
└─────────────────┘
I am wondering if it's possible to retain the original (escaped) representation of the input.
Thank you!

Answer 1

SELECT '{"message": "Hello \\"to\\" you!"}'
┌─'{"message": "Hello \\"to\\" you!"}'─┐
│ {"message": "Hello \"to\" you!"} │
└──────────────────────────────────────┘

Answer 2

Let's test your case without CLI to emulate the table filled by data coming outside:
echo '{"message": "Hello \"to\" you!"}' | clickhouse-client \
--password 12345 \
--query="INSERT INTO test.json_001 SELECT json FROM input('json String') FORMAT CSV"
create database test;
create table test.json_001 (json String) Engine=Memory;
Get required data:
clickhouse-client \
--password 12345 \
--query="SELECT JSONExtractRaw(json, 'message'), JSONExtractString(json, 'message') FROM test.json_001"
# result:
# "Hello \\"to\\" you!" Hello "to" you!
SELECT
JSONExtractRaw(json, 'message'),
JSONExtractString(json, 'message')
FROM test.json_001
/* result
┌─JSONExtractRaw(json, 'message')─┬─JSONExtractString(json, 'message')─┐
│ "Hello \"to\" you!" │ Hello "to" you! │
└─────────────────────────────────┴────────────────────────────────────┘
*/
It works as it should. I don't see any problems.