JDBC progress

JDBC_Example/JDBC_Example.iml

@@ -7,5 +7,15 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module-library">
+      <library>
+        <CLASSES>
+          <root url="file://$MODULE_DIR$/lib" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+        <jarDirectory url="file://$MODULE_DIR$/lib" recursive="false" />
+      </library>
+    </orderEntry>
   </component>
 </module>

JDBC_Example/src/com/papei/database/Main.java

@@ -1,8 +1,142 @@
 package com.papei.database;
 
+import java.sql.*;
+import java.util.Properties;
+
 public class Main
 {
-	public static void main(String[] args)
+	private static final String Domain = "localhost";
+	private static final int Port = 5432;
+	private static final String Database_Name = "ergasia";
+	private static final String Username = "thanos";
+	private static final String Password = "paravantis";
+	private static final String URL = "jdbc:postgresql://" + Domain + ":" + Port + "/" + Database_Name;
+	private static Connection conn;
+
+	public static void main(String[] args) throws ClassNotFoundException
+	{
+		Class.forName("org.postgresql.Driver");
+
+		try
+		{
+			conn = DriverManager.getConnection(URL, Username, Password);
+		}
+		catch (SQLException e)
+		{
+			System.out.println("Could not connect to PostgreSQL!");
+			e.printStackTrace();
+		}
+
+		execute2a();
+
+		System.out.println();
+
+		execute2b();
+
+		System.out.println();
+
+		execute2c();
+	}
+
+	private static void execute2a()
+	{
+		System.out.println("Erotima A");
+
+		Statement statement = null;
+		String query = "SELECT * FROM COUNT_MODELS WHERE COUNT_MODELS.num_of_model = (SELECT max(num_of_model) AS maximum FROM COUNT_MODELS);";
+		try
+		{
+			statement = conn.createStatement();
+			ResultSet res = statement.executeQuery(query);
+
+			System.out.println("ID\tTitle\tNumber of Models");
+
+			while (res.next())
+			{
+				String id = res.getString("id");
+				String title = res.getString("title");
+				String numberOfModels = res.getString("num_of_model");
+				System.out.println(id + "\t" + title + "\t" + numberOfModels);
+			}
+		}
+		catch (SQLException e)
+		{
+			e.printStackTrace();
+		}
+	}
+
+	private static void execute2b()
+	{
+		System.out.println("Erotima B");
+
+		Statement statement = null;
+		String query = "SELECT to_char(start_date, 'Month') as month, ROUND(AVG(cost)::numeric, 2) as avg_profit "
+				+ "FROM service_history "
+				+ "GROUP BY to_char(start_date, 'Month') "
+				+ "ORDER BY avg_profit DESC";
+
+		try
+		{
+			statement = conn.createStatement();
+			ResultSet res = statement.executeQuery(query);
+
+			System.out.println("Month\tAverage Profit");
+
+			while (res.next())
+			{
+				String month = res.getString("month");
+				String avgProfit = res.getString("avg_profit");
+				System.out.println(month + "\t" + avgProfit);
+			}
+		}
+		catch (SQLException e)
+		{
+			e.printStackTrace();
+		}
+	}
+
+	private static void execute2c()
+	{
+		System.out.println("Erotima C");
+
+		Statement statement = null;
+		String query = "SELECT salesman_id, employee.first_name, employee.last_name, profit "
+				+ "FROM PROFIT INNER JOIN employee ON PROFIT.salesman_id = employee.id "
+				+ "WHERE profit = (SELECT max(profit) FROM PROFIT);";
+
+		try
+		{
+			statement = conn.createStatement();
+			ResultSet res = statement.executeQuery(query);
+
+			System.out.println("ID\tFirst Name\tLastName\tProfit\t");
+
+			while (res.next())
+			{
+				String id = res.getString("salesman_id");
+				String firstName = res.getString("first_name");
+				String lastName = res.getString("last_name");
+				int profit = res.getInt("profit");
+				System.out.println(id + "\t" + firstName+ "\t" + lastName + "\t" + profit);
+			}
+		}
+		catch (SQLException e)
+		{
+			e.printStackTrace();
+		}
+	}
+
+	private static void execute2d()
+	{
+		//
+	}
+
+	private static void execute2e()
+	{
+		//
+	}
+
+	private static void execute2f()
 	{
 		//
 	}