1public class DatabaseSchema {
2    // Define the table names
3    private static final String USERS_TABLE = "users";
4    private static final String PAYMENTS_TABLE = "payments";
5    private static final String TRANSACTIONS_TABLE = "transactions";
6    private static final String PRODUCTS_TABLE = "products";
7
8    // Define the columns for each table
9    private static final String USER_ID_COLUMN = "user_id";
10    private static final String NAME_COLUMN = "name";
11    private static final String EMAIL_COLUMN = "email";
12    private static final String PASSWORD_COLUMN = "password";
13
14    private static final String PAYMENT_ID_COLUMN = "payment_id";
15    private static final String AMOUNT_COLUMN = "amount";
16    private static final String DATE_COLUMN = "date";
17    private static final String STATUS_COLUMN = "status";
18
19    private static final String TRANSACTION_ID_COLUMN = "transaction_id";
20    private static final String TYPE_COLUMN = "type";
21    private static final String DESCRIPTION_COLUMN = "description";
22    private static final String TRANSACTION_DATE_COLUMN = "transaction_date";
23
24    private static final String PRODUCT_ID_COLUMN = "product_id";
25    private static final String PRODUCT_NAME_COLUMN = "product_name";
26    private static final String PRICE_COLUMN = "price";
27    private static final String QUANTITY_COLUMN = "quantity";
28
29    // Define the relationships using foreign keys
30    private static final String USER_PAYMENT_FK = "fk_user_payment";
31    private static final String USER_TRANSACTION_FK = "fk_user_transaction";
32    private static final String PAYMENT_TRANSACTION_FK = "fk_payment_transaction";
33    private static final String PAYMENT_PRODUCT_FK = "fk_payment_product";
34
35    // Define the create table statements for each table
36    private static final String CREATE_USERS_TABLE =
37        "CREATE TABLE IF NOT EXISTS " + USERS_TABLE + " ("
38        + USER_ID_COLUMN + " INT PRIMARY KEY AUTO_INCREMENT, "
39        + NAME_COLUMN + " VARCHAR(100) NOT NULL, "
40        + EMAIL_COLUMN + " VARCHAR(100) NOT NULL, "
41        + PASSWORD_COLUMN + " VARCHAR(100) NOT NULL)";
42
43    private static final String CREATE_PAYMENTS_TABLE =
44        "CREATE TABLE IF NOT EXISTS " + PAYMENTS_TABLE + " ("
45        + PAYMENT_ID_COLUMN + " INT PRIMARY KEY AUTO_INCREMENT, "
46        + USER_ID_COLUMN + " INT NOT NULL, "
47        + AMOUNT_COLUMN + " DECIMAL(10,2) NOT NULL, "
48        + DATE_COLUMN + " DATE NOT NULL, "
49        + STATUS_COLUMN + " VARCHAR(20) NOT NULL, "
50        + FOREIGN KEY ("
51        + USER_ID_COLUMN + ") REFERENCES "
52        + USERS_TABLE + "(" + USER_ID_COLUMN + "), "
53        + "FOREIGN KEY ("
54        + PAYMENT_ID_COLUMN + ") REFERENCES "
55        + TRANSACTIONS_TABLE + "(" + TRANSACTION_ID_COLUMN + "), "
56        + "FOREIGN KEY ("
57        + PAYMENT_ID_COLUMN + ") REFERENCES "
58        + PRODUCTS_TABLE + "(" + PRODUCT_ID_COLUMN + "))";
59
60    private static final String CREATE_TRANSACTIONS_TABLE =
61        "CREATE TABLE IF NOT EXISTS " + TRANSACTIONS_TABLE + " ("
62        + TRANSACTION_ID_COLUMN + " INT PRIMARY KEY AUTO_INCREMENT, "
63        + USER_ID_COLUMN + " INT NOT NULL, "
64        + TYPE_COLUMN + " VARCHAR(50) NOT NULL, "
65        + DESCRIPTION_COLUMN + " VARCHAR(200) NOT NULL, "
66        + TRANSACTION_DATE_COLUMN + " DATE NOT NULL, "
67        + "FOREIGN KEY ("
68        + USER_ID_COLUMN + ") REFERENCES "
69        + USERS_TABLE + "(" + USER_ID_COLUMN + "))";
70
71    private static final String CREATE_PRODUCTS_TABLE =
72        "CREATE TABLE IF NOT EXISTS " + PRODUCTS_TABLE + " ("
73        + PRODUCT_ID_COLUMN + " INT PRIMARY KEY AUTO_INCREMENT, "
74        + PRODUCT_NAME_COLUMN + " VARCHAR(100) NOT NULL, "
75        + PRICE_COLUMN + " DECIMAL(10,2) NOT NULL, "
76        + QUANTITY_COLUMN + " INT NOT NULL)";
77
78    public static void main(String[] args) {
79        // Execute the create table statements
80        executeCreateTableStatement(CREATE_USERS_TABLE);
81        executeCreateTableStatement(CREATE_PAYMENTS_TABLE);
82        executeCreateTableStatement(CREATE_TRANSACTIONS_TABLE);
83        executeCreateTableStatement(CREATE_PRODUCTS_TABLE);
84
85        System.out.println("Tables created successfully!");
86    }
87
88    private static void executeCreateTableStatement(String createTableStatement) {
89        try (Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/payment_app", "username", "password");
90             Statement statement = connection.createStatement()) {
91
92            statement.execute(createTableStatement);
93
94        } catch (SQLException e) {
95            e.printStackTrace();
96        }
97    }
98}