import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
////////////////////////////
public class EPR
{
//-----------------------------

   public static void main(String args[])throws Exception
   {
	   try
	   {
	   String query1 = "select * from E";
	   String query2 = "select * from P";
	   String query3 = "select * from R";
	   String query4 = "select * from EPR";
	   String eid = "EID", ename = "ENAME", salary = "SALARY";  //columns of E table
	   String pid = "PID", projname = "PROJECTNAME"; //columns of P table
	   String rid = "RID", rolename = "ROLENAME";  //columns of R table

	   System.out.println("Printing table E:\n");
	   System.out.println(eid + "    " + ename + "    " + salary);
	   print(query1, eid, ename, salary);

	   System.out.println("Printing table P:\n");
	   System.out.println(pid + "    " + projname);
	   print(query2, pid, projname, null);

	   System.out.println("Printing table R:\n");
	   System.out.println(rid + "    " + rolename);
	   print(query3, rid, rolename, null);

	   System.out.println("Printing table EPR:\n");
	   System.out.println(eid + "    " + pid + "    " + rid);
	   print(query4, eid, pid, rid);

	   String url = "jdbc:odbc:Employee-Project-Role";

	   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

	   Connection con = DriverManager.getConnection(url);
	   Statement stmt = con.createStatement();


	   stmt.executeUpdate("insert into E values ('X555','Simons',44444)");
	   //stmt.executeUpdate("insert into EPR values (select EID from E where EID = 'X555', select PID from P where PID = 23, select RID from R where RID = 22)");
	   //stmt.executeUpdate("insert into EPR values (select EID = 'X555' from E, select PID = '23' from P, select RID = '22' from R)");
	   stmt.executeUpdate("INSERT INTO EPR VALUES ('X555',14,41)");

	   stmt.close();
	   con.close();

	   System.out.println("Printing table E:\n");
	   System.out.println(eid + "    " + ename + "    " + salary);
	   print(query1, eid, ename, salary);

	   System.out.println("Printing table P:\n");
	   System.out.println(pid + "    " + projname);
	   print(query2, pid, projname, null);

	   System.out.println("Printing table R:\n");
	   System.out.println(rid + "    " + rolename);
	   print(query3, rid, rolename, null);

	   System.out.println("Printing table EPR:\n");
	   System.out.println(eid + "    " + pid + "    " + rid);
	   print(query4, eid, pid, rid);
	   }catch(Exception ex)
	   {
		   System.out.println(ex);
	   }
   }
   public static void print(String qury, String colmn1, String colmn2, String colmn3)throws Exception
   {
      String url = "jdbc:odbc:Employee-Project-Role";

	  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

	  Connection con = DriverManager.getConnection(url);
	  Statement stmt = con.createStatement();
	  ResultSet rs = stmt.executeQuery(qury);
	  while (rs.next())
	  {
	     String column  = rs.getString(colmn1);
		 System.out.print(column + "    ");
		 column = rs.getString(colmn2);
		 System.out.print(column + "    ");
		 if(colmn3 != null)
		 {
			 column = rs.getString(colmn3);
			 System.out.print(column + "    \n");
		 }
		 else
			 System.out.println("");
	  }
	  System.out.println("");
	  rs.close();
	  stmt.close();
	  con.close();
   }

}