zrfFGeZg

1public class DbConnection {
2    private static DbConnection ourInstance = new DbConnection();
3
4    public static DbConnection getInstance() {
5        return ourInstance;
6    }
7
8    private final static String DRIVER = "org.sqlite.JDBC";
9    private final static String DATABASE = "jdbc:sqlite:Test.db";
10
11    private Connection connection = null;
12
13    private DbConnection() {
14        try {
15            Class.forName(DRIVER);
16            connection = DriverManager.getConnection(DATABASE);
17            createTable();
18        } catch (ClassNotFoundException e) {
19            e.printStackTrace();
20        } catch (SQLException e) {
21            e.printStackTrace();
22        }
23    }
24
25    public Connection getConnection() {
26        return connection;
27    }
28
29    public void createTable()
30    {
31        if (connection == null)
32        {
33            return;
34        }
35
36        try {
37            String sqlDoctor = "CREATE TABLE IF NOT EXISTS Doctor (" +
38                    "id INTEGER PRIMARY KEY NOT NULL," +
39                    "name VARCHAR(30)," +
40                    "surname VARCHAR(30)," +
41                    "specialization VARCHAR(20)" +
42                    ")";
43
44            String sqlPatient = "CREATE TABLE IF NOT EXISTS Patient (" +
45                    "id INTEGER PRIMARY KEY NOT NULL," +
46                    "name VARCHAR(30)," +
47                    "surname VARCHAR(30)," +
48                    "disease VARCHAR(20)" +
49                    ")";
50
51            String sqlVisit = "CREATE TABLE IF NOT EXISTS Visit (" +
52                    "id INTEGER PRIMARY KEY NOT NULL," +
53                    "doctor_id INTEGER NOT NULL," +
54                    "FOREIGN KEY (doctor_id) REFERENCES Doctor (id)," +
55                    "patient_id INTEGER NOT NULL," +
56                    "FOREIGN KEY (patient_id) REFERENCES Patient (id),"+
57                    "cost DOUBLE NOT NULL," +
58                    "date DATE" +
59                    ")";
60
61            Statement statement = connection.createStatement();
62            statement.execute(sqlDoctor);
63            statement.execute(sqlPatient);
64            statement.execute(sqlVisit);
65
66        } catch (SQLException e) {
67            e.printStackTrace();
68        }
69
70    }
71
72}