Throw a better error message when nonexistent column given to INSERT INTO statement

[derekjn]

For the following stream:

CREATE STREAM test_stream (x VARCHAR, y INTEGER)
  WITH (kafka_topic='test_topic', key='x', value_format='json', partitions=1);

And this INSERT:

INSERT INTO test_stream (x, nonexistent) VALUES ('x', 0);

This error will be thrown:

Failed to insert values into 'TEST_STREAM'. null

We should throw a more descriptive error in this case since we know exactly what the problem is.

[sakshiganeriwal]

@derekjn @apurvam I was looking into this issue, it looks like the exception message is being passed but the exception object itself is null:
https://github.com/confluentinc/ksql/blob/master/ksql-engine/src/main/java/io/confluent/ksql/engine/InsertValuesExecutor.java#L216
am i looking at the wrong place?

[apurvam]

It seems like the right place, but the the exception object seems not to have a message set. If the exception object was null, this should have been an NPE. did you try to inspect the exception thrown?