Saving a Spark-SQL file as csv - scala

Question

I am trying to save the output of SparkSQL to a path but not sure what function to use. I want to do this without using spark data frames. I was trying using write.mode("overwrite").csv("file:///home/user204943816622/Task_3a-out") but not successful. Can someone tell how to do it?
Note: spark SQL will give the output in multiple files. Need to ensure that the data is sorted globally across all the files (parts). So, all words in part 0, will be alphabetically before the words in part 1.
case class Docword(docId: Int, vocabId: Int, count: Int)
case class VocabWord(vocabId: Int, word: String)
// Read the input data
val docwords = spark.read.
schema(Encoders.product[Docword].schema).
option("delimiter", " ").
csv("hdfs:///user/bdc_data/t3/docword.txt").
as[Docword]
val vocab = spark.read.
schema(Encoders.product[VocabWord].schema).
option("delimiter", " ").
csv("hdfs:///user/bdc_data/t3/vocab.txt").
as[VocabWord]
docwords.createOrReplaceTempView("docwords")
vocab.createOrReplaceTempView("vocab")
spark.sql("""SELECT vocab.word AS word1, SUM(count) count1 FROM
docwords INNER JOIN vocab
ON docwords.vocabId = vocab.vocabId
GROUP BY word
ORDER BY count1 DESC""").show(10)
write.mode("overwrite").csv("file:///home/user204943816622/Task_3a-out")
// Required to exit the spark-shell
sys.exit(0)

Answer 1

.show() returns void you should dp something like below
val writeDf = spark.sql("""SELECT vocab.word AS word1, SUM(count) count1 FROM
docwords INNER JOIN vocab
ON docwords.vocabId = vocab.vocabId
GROUP BY word
ORDER BY count1 DESC""")
writeDf.write.mode("overwrite").csv("file:///home/user204943816622/Task_3a-out")
writeDf.show() // this should not be used in prod environment