Spark Convert Column to String

[Gibson]

Hi Folks,


Have created a UDF that queries a confluent schema registry for a schema,
which is then used within a Dataset Select with the from_avro function to
decode an avro encoded value (reading from a bunch of kafka topics)


Dataset<Row> recordDF = df.select(
        callUDF("getjsonSchemaUDF",col("topic").as("schema")),
        from_avro(col("avro_value"),
callUDF("getjsonSchemaUDF",col("topic"))).as("record")
);


from_avro expects a String type as the second argument, and not a column
type

I need to be able convert the jsonSchema returned from Col to String type

Any ideas