CREATE TABLE Department (
    department_id INT PRIMARY KEY,
    department_name VARCHAR(100) NOT NULL
);

CREATE TABLE Doctor (
    doctor_id INT PRIMARY KEY,
    doctor_name VARCHAR(100) NOT NULL,
    specialization VARCHAR(100),
    department_id INT,
    FOREIGN KEY (department_id)
    REFERENCES Department(department_id)
);

CREATE TABLE Patient (
    patient_id INT PRIMARY KEY,
    patient_name VARCHAR(100) NOT NULL,
    phone VARCHAR(15),
    email VARCHAR(100)
);

CREATE TABLE Appointment (
    appointment_id INT PRIMARY KEY,
    patient_id INT,
    doctor_id INT,
    appointment_date DATE,
    status VARCHAR(50),
    FOREIGN KEY (patient_id)
    REFERENCES Patient(patient_id),
    FOREIGN KEY (doctor_id)
    REFERENCES Doctor(doctor_id)
);

CREATE TABLE Prescription (
    prescription_id INT PRIMARY KEY,
    appointment_id INT,
    diagnosis VARCHAR(255),
    medicine VARCHAR(255),
    FOREIGN KEY (appointment_id)
    REFERENCES Appointment(appointment_id)
);

CREATE TABLE Bill (
    bill_id INT PRIMARY KEY,
    patient_id INT,
    amount DECIMAL(10,2),
    payment_status VARCHAR(50),
    FOREIGN KEY (patient_id)
    REFERENCES Patient(patient_id)
);