In Spark-SQL CLI tool, the result print will omit headings (column names) by default. To display columns, we need to update Spark setting spark.hadoop.hive.cli.print.header.
Update Spark defaults file
To make the changes for all spark-sql sessions, edit file $SPARK_HOME/conf/spark-defaults.conf.
Add the following line into the file:
spark.hadoop.hive.cli.print.header true
Pass config value when starting session
If you only want to make this config effective for the session, start spark-sql CLI with the following argument:
spark-sql --conf "spark.hadoop.hive.cli.print.header=true"