Self join

Dataset<Row> ff =  spark.read()
				.option("inferSchema",true)
				.option("header", "true")
				.csv("/home/hasura/Desktop/SparkData/emp.csv");
	
		Dataset<Row> ff1 = ff;
		
		//ff.join(ff1, ff.col("empid").equalTo(ff1.col("mid"))).show();
		
		  ff.as("a")
		 .join(ff.as("b"))
		 .where("a.empid = b.mid")
		 
		 .selectExpr("b.name as employee"," a.name as Employer")
		 
		 .show();