Running SQL Queries Programmatically

The sql function on a SparkSession enables applications to run SQL queries programmatically and returns the result as a DataFrame.

df.createOrReplaceTempView("people")
spark.sql("select * from people").show()
/*
+----+-------+
| age|   name|
+----+-------+
|null|Michael|
|  30|   Andy|
|  19| Justin|
+----+-------+
*/