text: CREATE TABLE Caregivers (
      Username varchar(255),
      Salt BINARY(16),
      Hash BINARY(16),
      PRIMARY KEY (Username)
  );
  
  CREATE TABLE Availabilities (
      Time date,
      Username varchar(255) REFERENCES Caregivers,
      PRIMARY KEY (Time, Username)
  );
  
  CREATE TABLE Vaccines (
      Name varchar(255),
      Doses int,
      PRIMARY KEY (Name)
  );
  
  CREATE TABLE Patients (
      Username varchar(255),
      Salt BINARY(16),
      Hash BINARY(16),
      PRIMARY KEY (Username)
  );
  
  CREATE TABLE Reserve (
  	appointment_id varchar(255),
  	Time date,
  	Vaccine_name varchar(255) REFERENCES Vaccines,
  	P_Username varchar(255) REFERENCES Patients,
  	C_Username varchar(255) REFERENCES Caregivers,
  	PRIMARY KEY(appointment_id)
  );