Cannot convert CHOICE, type must be explicit

fzalila — Thu, 20 Feb 2020 21:32:59 GMT

Hi all
I have the following Nifi template which ingests data from a csv file and put them in a database.

The template is available here
https://github.com/cetic/fadi/blob/master/examples/basic/basic_example_final_template.xml

The template is composed of two processes InvokeHTTP and PutDatabaseRecord

InvokeHTTPPutDatabase

It has also two controller services : CSV Reader and DBCPCOnnectionPool

The complete explanation of this small example is available here
https://github.com/cetic/fadi/blob/master/USERGUIDE.md#3-ingest-measurements

The csv file is here
https://raw.githubusercontent.com/cetic/fadi/master/examples/basic/sample_data.csv

The table creation is:

CREATE TABLE example_basic (
measure_ts TIMESTAMP NOT NULL,
temperature FLOAT (50)
);

Until Apache Nifi 1.9.2 everything works are expected!
Since Apache Nifi 10.0.0, I have an Error in the PutDatabaseRecord processor

"org.apache.nifi.serialization.record.util.IllegalTypeConversionException: Cannot convert CHOICE, type must be explicit"

It seems to be related to this https://github.com/apache/nifi/blob/master/nifi-commons/nifi-record/src/main/java/org/apache/nifi/serialization/record/util/DataTypeUtils.java#L1733

Any idea how can I edit the template to fix this error?

Re: Cannot convert CHOICE, type must be explicit

fzalila — Thu, 20 Feb 2020 21:41:30 GMT

I tried to update the schema text of CSV reader with the following content:

{
"type" : "record",
"name" : "userInfo",
"namespace" : "my.example",
"fields" : [{"name" : "measure_ts", "type" : {
"type" : "long",
"logicalType" : "timestamp-millis"
}},{"name" : "temperature", "type" : "long"}]
}

but always the same error !

Re: Cannot convert CHOICE, type must be explicit

fzalila — Tue, 25 Feb 2020 14:01:09 GMT

The solution is to change the schema access strategy to Use String Fields From Header.

question Re: Cannot convert CHOICE, type must be explicit in Support Questions

Cannot convert CHOICE, type must be explicit

Re: Cannot convert CHOICE, type must be explicit

Re: Cannot convert CHOICE, type must be explicit