add UkMarketSpaces join

Author: James Lee

src/main/java/com/sparkTutorial/sparkSql/join/UkMarketSpaces.java

@@ -0,0 +1,30 @@
+package com.sparkTutorial.sparkSql.join;
+
+import org.apache.log4j.Level;
+import org.apache.log4j.Logger;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+
+public class UkMarketSpaces {
+
+    public static void main(String[] args) throws Exception {
+
+        Logger.getLogger("org").setLevel(Level.ERROR);
+
+        SparkSession session = SparkSession.builder().appName("StackOverFlowSurvey").master("local[1]").getOrCreate();
+
+        Dataset<Row> marketSpace = session.read().option("header", "true").csv("in/uk-market-spaces-identifiable-data.csv");
+        Dataset<Row> postCode = session.read().option("header", "true").csv("in/uk-postcode.csv");
+
+
+        postCode.show();
+        marketSpace.show();
+
+        Dataset<Row> joined = marketSpace.join(postCode, marketSpace.col("Postcode").startsWith(postCode.col("Postcode")));
+
+        joined.show();
+
+        joined.groupBy("Region").count().show(200);
+    }
+}