CREATE TABLE fees (
    id INT AUTO_INCREMENT PRIMARY KEY,
    reg_id INT NOT NULL,
    amount DECIMAL(10,2) NOT NULL,
    paid_on DATE NOT NULL,
    mode VARCHAR(50) DEFAULT 'Cash', -- Payment Mode (Cash/UPI/Card/Online)
    remark VARCHAR(255) NULL,
    FOREIGN KEY (reg_id) REFERENCES registrations(reg_id) ON DELETE CASCADE
);