text: CREATE TABLE IF NOT EXISTS customers (
      customer_id BIGINT PRIMARY KEY AUTO_INCREMENT,
      name VARCHAR(40) NOT NULL,
      phone_number VARCHAR(20) NOT NULL,
      notes varchar(255)
  );
  
  CREATE TABLE IF NOT EXISTS employees (
      employee_id BIGINT PRIMARY KEY AUTO_INCREMENT,
      name VARCHAR(40) NOT NULL
  );
  
  CREATE TABLE IF NOT EXISTS employees_skills (
      skill_name VARCHAR(50) NOT NULL,
      employee_id BIGINT NOT NULL,
      FOREIGN KEY (employee_id)  REFERENCES employees (employee_id)
  );
  
  CREATE TABLE IF NOT EXISTS employees_availability (
      weekday VARCHAR(40) NOT NULL,
      employee_id BIGINT NOT NULL,
      FOREIGN KEY (employee_id)  REFERENCES employees (employee_id)
  );
  
  CREATE TABLE IF NOT EXISTS pets (
      pet_id BIGINT PRIMARY KEY AUTO_INCREMENT,
      name VARCHAR(40) NOT NULL,
      type VARCHAR(15) NOT NULL,
      birth_date DATE,
      notes varchar(255),
      owner_id BIGINT NOT NULL,
      FOREIGN KEY (owner_id)  REFERENCES customers (customer_id)
  );
  
  CREATE TABLE IF NOT EXISTS schedules (
      schedule_id BIGINT PRIMARY KEY AUTO_INCREMENT,
      delivery_date DATE NOT NULL,
      activities varchar(255) NOT NULL
  );
  
  CREATE TABLE IF NOT EXISTS schedules_pets (
      schedule_id BIGINT NOT NULL,
      pet_id BIGINT NOT NULL,
      FOREIGN KEY (pet_id)  REFERENCES pets (pet_id),
      FOREIGN KEY (schedule_id)  REFERENCES schedules (schedule_id)
  );
  
  CREATE TABLE IF NOT EXISTS schedules_employees (
      schedule_id BIGINT NOT NULL,
      employee_id BIGINT NOT NULL,
      FOREIGN KEY (employee_id)  REFERENCES employees (employee_id),
      FOREIGN KEY (schedule_id)  REFERENCES schedules (schedule_id)
  );
  