How to fix Expected start-union. Got VALUE_NUMBER_INT when converting JSON to Avro on the command line?

Question

I\'m trying to validate a JSON file using an Avro schema and write the corresponding Avro file. First, I\'ve defined the following Avro schema named user.avsc:<

Answer 1

According to the explanation by Doug Cutting,

Avro's JSON encoding requires that non-null union values be tagged with their intended type. This is because unions like ["bytes","string"] and ["int","long"] are ambiguous in JSON, the first are both encoded as JSON strings, while the second are both encoded as JSON numbers.

http://avro.apache.org/docs/current/spec.html#json_encoding

Thus your record must be encoded as:

{"name": "Alyssa", "favorite_number": {"int": 7}, "favorite_color": null}