Hi Shengnan,
Yes. Flink 1.9 supports nested json derived. You should declare the ROW
type with nested schema explicitly. I tested a similar DDL against 1.9.0
RC2 and worked well.
CREATE TABLE kafka_json_source (
rowtime VARCHAR,
user_name VARCHAR,
event ROW<message_type VARCHAR, message VARCHAR>
) WITH (
'connector.type' = 'kafka',
'connector.version' = 'universal',
'connector.topic' = 'test-json',
'connector.startup-mode' = 'earliest-offset',
'connector.properties.0.key' = 'zookeeper.connect',
'connector.properties.0.value' = 'localhost:2181',
'connector.properties.1.key' = 'bootstrap.servers',
'connector.properties.1.value' = 'localhost:9092',
'update-mode' = 'append',
'format.type' = 'json',
'format.derive-schema' = 'true'
);
The kafka message is
{"rowtime": "2018-03-12T08:00:00Z", "user_name": "Alice", "event": {
"message_type": "WARNING", "message": "This is a warning."}}
Thanks,
Jark
On Thu, 15 Aug 2019 at 14:12, Shengnan YU <[email protected]> wrote:
>
> Hi guys
> I am trying the DDL feature in branch 1.9-releasae. I am stucked in
> creating a table from kafka with nested json format. Is it possibe to
> specify a "Row" type of columns to derive the nested json schema?
>
> String sql = "create table kafka_stream(\n" +
> " a varchar, \n" +
> " b varchar,\n" +
> " c int,\n" +
> " inner_json row\n" +
> ") with (\n" +
> " 'connector.type' ='kafka',\n" +
> " 'connector.version' = '0.11',\n" +
> " 'update-mode' = 'append', \n" +
> " 'connector.topic' = 'test',\n" +
> " 'connector.properties.0.key' = 'bootstrap.servers',\n" +
> " 'connector.properties.0.value' = 'localhost:9092',\n" +
> " 'format.type' = 'json', \n" +
> " 'format.derive-schema' = 'true'\n" +
> ")\n";
>
> Thank you very much!
>
