Add and delete directly from PostgreSQL from Spark and Scala - scala

Question

I would like to compare the size of two DataFrames that have been extracted from Oracle and PostgreSQL databases. I would like to compare them, then either add new rows or delete rows. How does one directly add or delete from PostreSQL? Here is what I did:
System.setProperty("hadoop.home.dir", "C:\\hadoop");
System.setProperty("spark.sql.warehouse.dir", "file:///C:/spark-warehouse");
val sparkSession = SparkSession.builder.master("local").appName("spark session example").getOrCreate()
//connect to table TMP_STRUCTURE oracle
val spark = sparkSession.sqlContext
val df = spark.load("jdbc",
Map("url" -> "jdbc:oracle:thin:System/maher#//localhost:1521/XE",
"dbtable" -> "IPTECH.TMP_STRUCTURE"))
import sparkSession.implicits._
val usedGold = df.filter(length($"CODE") === 2) // get column with length equal to 2
val article_groups = spark.load("jdbc", Map(
"url" -> "jdbc:postgresql://localhost:5432/gemodb?user=postgres&password=maher",
"dbtable" -> "article_groups")).select("id", "name")
val usedArticleGroup = article_groups.select($"*", $"id".cast(StringType) as "newId") // cast column code to Long
val usedPostg = usedArticleGroup.select("newId", "name")
// val df3 = usedGold.join(usedPostg, $"code" === $"newId", "outer")
//get different rows
val differentData = usedGold.except(usedPostg).toDF("code", "name")
if (usedGold.count > usedPostg.count) {
//insert into usedPostg values(differentData("code"),differentData("name"))
} else if (usedGold.count < usedPostg.count) {
// delete from usedPostg where newId= differentData("code") in postgresql
}