BigQuery sink generates incorrect query when using all the input fields in relationTableKey field
Steps to reproduce,
1. Create a pipeline with simple source that connects to a bq sink
2. In the BQ sink add all the fields from input schema to relationTableKey property (Table Key).
3. Deploy the pipeline and run.
The SQL query that is generated from BQ sink configuration has syntax error and the pipelines fails to write it to BQ sink.
Have attached a sample pipeline for reference.
The SQL query generated was,
Notice the WHEN clause is incorrectly generated.
Actual exception from logs