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apache-flinkflink-streamingflink-sql

Field types of query result and registered TableSink do not match

The query result schema printed by table.printSchema():

 |-- deviceId: BIGINT
 |-- channel: STRING
 |-- schemaId: BIGINT
 |-- productId: BIGINT
 |-- schema: LEGACY('RAW', 'ANY<com.yunmo.iot.schema.Schema>')

bug when excuting table.toRetractStream[DeviceSchema].print(), exception throwed:

Exception in thread "main" org.apache.flink.table.api.ValidationException: Field types of query result and registered TableSink  do not match.
Query schema: [deviceId: BIGINT, channel: STRING, schemaId: BIGINT, productId: BIGINT, schema: RAW('com.yunmo.iot.schema.Schema', ?)]
Sink schema: [deviceId: BIGINT, channel: STRING, schemaId: BIGINT, productId: BIGINT, schema: LEGACY('RAW', 'ANY<com.yunmo.iot.schema.Schema>')]

The com.yunmo.iot.schema.Schema is a generic type.

The schema field of Query schema change from LEGACY('RAW' to RAW, but the Sink schema still a LEGACY('RAW'

Solution

  • Unfortunately, the type system rework of Flink's Table & SQL API is not completed yet and maybe not all layers play nicely together. How did you define your data type? Are you mixing DataType and the deprecated Types? Using Types consistently should solve the problem for now. Otherwise, feel free to open an issue on Flink's issue tracker.