how to do count in flink sql - sql

Question

I'd like to do count(0)in flink SQL, but it gives exception like
org.apache.flink.client.program.ProgramInvocationException: The main method caused an error: SQL parse failed. UDT in DDL is not supported yet.
don't know is there anything wrong?
expect the output should work fine
INSERT INTO request_join
select requestId,count(0) from requests
GROUP BY TUMBLE(rowtime, INTERVAL '1' HOUR),requestId;
The schema of the table is here
name: request_join
schema:
- '`requestId` VARCHAR'
- '`count` LONG'
properties:
'connector.type': 'kafka'
'connector.version': 'universal'
'connector.topic': 'request_join_test'
'connector.startup-mode': 'latest-offset'
'connector.properties.0.key': 'zookeeper.connect'
'connector.properties.0.value': '10.XXXXXXXXX'
'connector.properties.1.key': 'bootstrap.servers'
'connector.properties.1.value': '10.XXXXXXXXX'
'connector.properties.2.key': 'group.id'
'connector.properties.2.value': 'request_join_test'
'update-mode': 'append'
'format.type': 'json'
'format.json-schema': '{type: "object", properties: {requestId: { type: "string"},count:{type:
"number"}}}'
didn't find anything wrong, but it just doesn't work, if I do not count and delete the count from the schema it will work well so I'm sure the sql itself is good.
I checked the flink sql it says some of the functions are not supported in DDL, so don't flink support count? I can see from examples that it support SUM very well.

Answer 1

There is sth wrong with your schema,
schema:
- 'requestId VARCHAR'
- 'count BIGINT'