Please draw ER diagram

CREATE DATABASE company;

USE company;

CREATE TABLE patients ( patient_id number(20) PRIMARY KEY, name VARCHAR2(50) NOT NULL, address VARCHAR2(100) NOT NULL, phone_number VARCHAR2(15) NOT NULL );

CREATE TABLE doctors ( doctor_id number(20) PRIMARY KEY, name VARCHAR(50) NOT NULL, specialty VARCHAR(50) NOT NULL, years_of_experience INT NOT NULL );

CREATE TABLE clinics ( clinic_id number(20) PRIMARY KEY, name VARCHAR(50) NOT NULL, address VARCHAR(100) NOT NULL, phone_number VARCHAR(15) NOT NULL );

CREATE TABLE appointments ( appointment_id number(20) PRIMARY KEY, patient_id number(20) NOT NULL, doctor_id number(20) NOT NULL, clinic_id number(20) NOT NULL, appointment_date DATE NOT NULL, FOREIGN KEY (patient_id) REFERENCES patients(patient_id), FOREIGN KEY (doctor_id) REFERENCES doctors(doctor_id), FOREIGN KEY (clinic_id) REFERENCES clinics(clinic_id) );