Please help with this lab assignment - Java

Chapter 16 Lab - Databases Lab Objectives Be able to write SQL statements. Be able to retrieve information from a database. Be able to add information to a database. Be able to change information in multiple tables of the database. Introduction A recreation director needs to keep track of summer T-ball teams, games, and season records. He has hired you to write an computer program to make his life easier. You have created a menu driven program that allows the director to use a database to easily manipulate teams, games, and scores. It also allows the database to be refreshed for a new year. Complete the tasks below to enable all the functionality that is required for this application. Task #1 Database connection and initialization 1. Copy the file TeamDB.java (see code listing 16.1) from the Student CD or as directed by your instructor. 2. Modify the DRIVER and DB_URL constants at the beginning of the main method as directed by your instructor to connect with your database correctly. 3. Create and initialize the database by running the program and selecting option 6. 4. If at any point after the initialization, you wish to start over, you can select option 6, which will remove the database tables and recreate and initialize them. 5. The Teams table created and initialized in the database is as follows: TeamName Wins Losses Ties Astros 0 0 0 Brewers 0 0 0 Cubs 0 0 0 Marlins 0 0 0 6. The Games table created and initialized in the database is as follows: GameNumber HomeTeam HomeTeamScore VisitorTeam VisitorTeamScore 1 Astros 0 Brewers 0 2 Brewers 0 Cubs 0 3 Cubs 0 Astros 0 Task #2 Retrieve information using SQL 1. Select option 1 to view the teams. Your output should be as follows: Team Name Win Lose Tie Astros 0 0 0 Brewers 0 0 0 Cubs 0 0 0 Marlins 0 0 0 2. Write the implementation for the viewSchedule method. a. Write an SQL statement to select all columns from the Games table. b. Execute the query by sending the SQL statement to the DBMS. c. Use a while loop to display the contentsof the result set to the monitor. d. Compile and run the program. Selectoption 2 and your output should be as follows: GameID Home Score Visitor Score 1 Astros 0 Brewers 0 2 Brewers 0 Cubs 0 3 Cubs 0 Astros 0 Task #3 Add information using SQL 1. Write the body of the loop in the addTeams method. You should prompt the user for the new team name, write the SQL statement and update the Teams table with the new team name. 2. Compile and run the program. Select option 3 and enter Braves. Enter N to stop entering names. Select option 1 again toview the teams. Your output should now look like: Team Name Win Lose Tie Astros 0 0 0 Braves 0 0 0 Brewers 0 0 0 Cubs 0 0 0 Marlins 0 0 0 Task #4 Change information inmultiple tables using SQL 1. Edit the enterScores method. Execute a query using the appropriate SQL statement to get the result set containing all information for the gameNumber the user entered. 2. After the user inputs the scores for both teams, execute updates to the Games table using the appropriate SQL statements. 3. In each branch of the logic determining winner, loser or tie: retrieve the number from the appropriate column (losses, wins, or ties) from the Teams table for one of the teams, increment it, and update the table for that team. Do the same for the opposing team. 4. Select option 5 to enter scores. Enter scores as follows: Game 1 Astros 5 Brewers 3 Game 2 Brewers 4 Cubs 4 Game 3 Cubs 1 Astros 6

CODE:

import java.sql.*; import java.util.Scanner; public class TeamDB { public static void main(String[] args) { // Create constants for the driver name and URL. // NOTE: These values are specific for Cloudscape. final String DRIVER = "org.apache.derby.jdbc.EmbeddedDriver"; final String DB_URL = "jdbc:derby:TeamDB;create=true"; Connection conn; try { // Load the JDBC driver. Class.forName(DRIVER).newInstance(); // Create a connection to the database. conn = DriverManager.getConnection(DB_URL); char choice; Scanner keyboard = new Scanner(System.in); System.out.println("Welcome to the Sports Teams Database Manager!"); do { printMenu(); choice = keyboard.nextLine().charAt(0); switch (choice) { case '0': // Close the connection. conn.close(); break; case '1': viewTeams(conn); break; case '2': viewSchedule(conn); break; case '3': addTeams(conn); break; case '4': addGames(conn); break; case '5': enterScores(conn); break; case '6': beginNewSeason(conn); break; } }while (choice != '0'); } catch(Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); } } /***************************************************** // The printMenu method displays the menu choices for* // the user to work with the database * //****************************************************/ public static void printMenu() { System.out.println(); System.out.println("Select from the following options:"); System.out.println("1. View team standings"); System.out.println("2. View the schedule"); System.out.println("3. Add a team"); System.out.println("4. Add a game to the schedule"); System.out.println("5. Enter game scores"); System.out.println("6. Begin a new season"); System.out.println("0. Exit the program"); } /***************************************************** * Utility method to remove the tables and allow the * user to reset the database for a new season * @param conn Connection to the database ****************************************************/ public static void beginNewSeason(Connection conn) { try { Statement stmt = conn.createStatement(); //remove tables if database tables have been created //this will throw an exception if the tables do not exist stmt.execute("DROP TABLE Games"); stmt.execute("DROP TABLE Teams"); //once the tables have been removed, call the method to //create and initialize the tables System.out.println("Reinitializing database for a new season"); createTeamDB(conn); } catch (Exception ex) { //call the method to create tables for the database System.out.println("Creating database for the first time"); createTeamDB(conn); } } /****************************************************** * Utility method to create the tables and initialize * the database with teams and games. * @param conn Connection to the database ******************************************************/ public static void createTeamDB(Connection conn) { try { Statement stmt = conn.createStatement(); //create the table of teams stmt.execute("CREATE TABLE Teams (" + "TeamName CHAR(15) NOT NULL PRIMARY KEY, " + "Wins INT, " + "Losses INT, " + "Ties INT" + ")"); //add some teams stmt.executeUpdate("INSERT INTO Teams " + "(TeamName) " + "VALUES ('Astros')"); stmt.executeUpdate("INSERT INTO Teams " + "(TeamName) " + "VALUES ('Marlins')"); stmt.executeUpdate("INSERT INTO Teams " + "(TeamName) " + "VALUES ('Brewers')"); stmt.executeUpdate("INSERT INTO Teams " + "(TeamName) " + "VALUES ('Cubs')"); //create a listing of the games to be played stmt.execute("CREATE TABLE Games (" + "GameNumber INT NOT NULL PRIMARY KEY, " + "HomeTeam CHAR(15) NOT NULL REFERENCES Teams (TeamNumber), " + "HomeTeamScore INT, " + "VisitorTeam CHAR(15) NOT NULL REFERENCES Teams (TeamNumber), " + "VisitorTeamScore INT" + ")"); stmt.executeUpdate("INSERT INTO Games " + "(GameNumber, HomeTeam, VisitorTeam) " + "VALUES (1, 'Astros', 'Brewers')"); stmt.executeUpdate("INSERT INTO Games " + "(GameNumber, HomeTeam, VisitorTeam) " + "VALUES (2, 'Brewers', 'Cubs')"); stmt.executeUpdate("INSERT INTO Games " + "(GameNumber, HomeTeam, VisitorTeam) " + "VALUES (3, 'Cubs','Astros')"); } catch (Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); } } /******************************************************** * Allows the user to add more teams to the database * @param conn *******************************************************/ public static void addTeams(Connection conn) { Scanner keyboard = new Scanner (System.in); try { char ans; String teamName; Statement stmt = conn.createStatement(); do { //********************************************* // Task 3 //prompt the user for a new team name //write SQL statement and update the Teams table //********************************************** System.out.print("Do you want to enter another team: "); ans = keyboard.nextLine().charAt(0); }while (ans == 'Y'|| ans == 'y'); } catch (Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); } } /************************************************************** * Allows the user to add games to the schedule. A unique * game number is created for each game on the schedule. * The user will need to supply a home team name and a visitor * team name from the keyboard. * @param conn Connection to the database *************************************************************/ public static void addGames(Connection conn) { Scanner keyboard = new Scanner (System.in); try { char ans; String homeTeam; String visitingTeam; int gameNumber = 1; Statement stmt = conn.createStatement(); //This retrieves the retrieves the data and allows you to count //the number of games already scheduled so that you add a unique game number String sqlStatement = "SELECT * from Games"; ResultSet result = stmt.executeQuery(sqlStatement); while (result.next()) { gameNumber++; } do { System.out.print("Enter the home team name: "); homeTeam = keyboard.nextLine(); System.out.print("Enter the visiting team number: "); visitingTeam = keyboard.nextLine(); sqlStatement = "INSERT INTO Games " + "(GameNumber, HomeTeam, VisitorTeam) " + "VALUES ('" + gameNumber + "', '" + homeTeam + "', '" + visitingTeam + "')"; stmt.executeUpdate(sqlStatement); System.out.print("Do you want to enter another game: "); ans = keyboard.nextLine().charAt(0); }while (ans == 'Y'|| ans == 'y'); } catch (Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); } } /********************************************************** * Displays a table listing the team names and season records. * Since teams have not yet played, all numbers are zero. * @param conn Connection to the database **********************************************************/ public static void viewTeams(Connection conn) { try { // Create a Statement object. Statement stmt = conn.createStatement(); // Create a string with a SELECT statement. String sqlStatement = "SELECT * FROM Teams"; // Send the statement to the DBMS. ResultSet result = stmt.executeQuery(sqlStatement); System.out.printf("%-15s %10s %10s %10s ", "Team Name", "Win", "Lose", "Tie"); // Display the contents of the result set. // The result set will have 5 columns. while (result.next()) { System.out.printf("%-15s %10d %10d %10d ", result.getString("TeamName"), result.getInt("Wins"), result.getInt("Losses"), result.getInt("Ties")); } } catch(Exception ex) { System.out.println("ERROR: " + ex.getMessage()); } } /*********************************************************** * Retrieves and displays the teams and scores for all games. * @param conn Connection to the database ***********************************************************/ public static void viewSchedule(Connection conn) { try { // Create a Statement object. Statement stmt = conn.createStatement(); //********************************** // TASK 2 // Create a string with a SELECT statement. // Send the statement to the DBMS. //******************************************* //This is a suggested column headings display System.out.println("List of games and scores:"); System.out.printf("%-6s %-20s %6s %-20s %6s ", "GameID", "Home", "Score", "Visitor", "Score"); //********************************************* // Task 2-2c // Use a while loop to display the contents of the // result set.The result set will have five columns. //************************************************ } catch(Exception ex) { System.out.println("ERROR: " + ex.getMessage()); } } /************************************************************ * Allows user to enter scores for both teams. The method will * update the Games table with the scores entered. It will * also compare the scores to determine the winning and losing * teams (or tie) and update the appropriate column in the * Teams table for each team involved in the game. * @param conn Connection to the database ************************************************************/ public static void enterScores(Connection conn) { Scanner keyboard = new Scanner (System.in); try { char ans; int gameNumber; String homeTeam; String visitingTeam; int score1; int score2; String sqlStatement; ResultSet result; Statement stmt = conn.createStatement(); do { System.out.print("Enter the game ID: "); gameNumber = keyboard.nextInt(); //************************************************************ // TASK 4-1 // Get the result set from a query that selects all information // for the gameNumber the user entered. //************************************************************ if(result.next()) { homeTeam = result.getString("HomeTeam"); visitingTeam = result.getString("VisitorTeam"); System.out.print("Enter the score for the " + homeTeam); score1 = keyboard.nextInt(); System.out.print("Enter the score for the " + visitingTeam); score2 = keyboard.nextInt(); keyboard.nextLine(); //************************************************************** // Task 4-2 // Execute an update to the Games table to store the score for // each team of that game number //************************************************************** if (score1 < score2) { //************* DONE FOR YOU ******************************* // Task 4-3 // Retrieve the number from the appropriate column // (wins, losses, or ties) for the home team, increment, and // update that team's record. Do the same for the visiting team. result = stmt.executeQuery("SELECT Losses FROM Teams " + " WHERE TeamName = " + "'" + homeTeam + "'"); if(result.next()) { int losses = result.getInt("Losses"); stmt.executeUpdate("UPDATE Teams " + "SET Losses = " + (losses+1) + " WHERE TeamName = " + "'" + homeTeam + "'"); } result = stmt.executeQuery("SELECT Wins FROM Teams " + " WHERE TeamName = " + "'" + visitingTeam + "'"); if(result.next()) { int wins = result.getInt("Wins"); stmt.executeUpdate("UPDATE Teams " + "SET Wins = " + (wins+1) + " WHERE TeamName = " + "'" + visitingTeam + "'"); } //************************************************************** } else if (score2 < score1) { //************* DONE FOR YOU ******************************* // Task 4-3 // Retrieve the number from the appropriate column // (wins, losses, or ties) for the home team, increment, and // update that team's record. Do the same for the visiting team. result = stmt.executeQuery("SELECT Losses FROM Teams " + " WHERE TeamName = " + "'" + visitingTeam + "'"); if (result.next()) { int losses = result.getInt("Losses"); stmt.executeUpdate("UPDATE Teams " + "SET Losses = " + (losses+1) + " WHERE TeamName = " + "'" + visitingTeam + "'"); } result = stmt.executeQuery("SELECT Wins FROM Teams " + " WHERE TeamName = " + "'" + homeTeam + "'"); if (result.next()) { int wins = result.getInt("Wins"); stmt.executeUpdate("UPDATE Teams " + "SET Wins = " + (wins+1) + " WHERE TeamName = " + "'" + homeTeam + "'"); } //******************************************************* } else { //************* DONE FOR YOU ******************************* // Task 4-3 // Retrieve the number from the appropriate column // (wins, losses, or ties) for the home team, increment, and // update that team's record. Do the same for the visiting team. int ties; result = stmt.executeQuery("SELECT Ties FROM Teams " + " WHERE TeamName = " + "'" + homeTeam + "'"); if (result.next()) { ties = result.getInt("Ties"); stmt.executeUpdate("UPDATE Teams " + "SET Ties = " + (ties+1) + " WHERE TeamName = " + "'" + homeTeam + "'"); } System.out.println(1); result = stmt.executeQuery("SELECT Ties FROM Teams " + " WHERE TeamName = " + "'" + visitingTeam + "'"); System.out.println(2); if(result.next()) { ties = result.getInt("Ties"); System.out.println(3); stmt.executeUpdate("UPDATE Teams " + "SET Ties = " + (ties+1) + " WHERE TeamName = " + "'" + visitingTeam + "'"); } //******************************************************* } } System.out.print("Do you want to enter another game: "); ans = keyboard.nextLine().charAt(0); }while (ans == 'Y'|| ans == 'y'); } catch (Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); } } } 

5. Select option 1 to view the team standingsand option 2 to see the scores. Your output should now be Team Name Win Lose Tie Astros 2 0 0 Braves 0 0 0 Brewers 0 1 1 Cubs 0 1 1 Marlins 0 0 0 List of games and scores: GameID Home Score Visitor Score 1 Astros 5 Brewers 3 2 Brewers 4 Cubs 4 3 Cubs 1 Astros 6

Additional Java File

import java.sql.Connection;

import java.sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; import java.util.Scanner;

public class DeleteTables {

public static void main(String[] args) { // TODO Auto-generated method stub

final String DRIVER = "org.apache.derby.jdbc.EmbeddedDriver"; final String DB_URL = "jdbc:derby:TeamDB;create=true";

Connection conn; try { // Load the JDBC driver. Class.forName(DRIVER).newInstance();

// Create a connection to the database. conn = DriverManager.getConnection(DB_URL);

Statement stmt = conn.createStatement();

// remove tables if database tables have been created // this will throw an exception if the tables do not exist // stmt.execute("DROP TABLE Games"); stmt.execute("DROP TABLE Teams"); } catch (Exception ex) { System.out.println("ERROR: " + ex.getMessage()); ex.printStackTrace(); }

} }