title: Why do I keep getting unique constraint violated?
body: <pre><code>create table Doctor
  (
      docID INTEGER,
      appointID INTEGER not null,
      regnum CHAR(6),   
      doc_name VARCHAR(40),
      doc_gender CHAR(1),
      qual VARCHAR(80),       
  
      primary key (docID),
      foreign key (appointID) references Appointment
  );
  
  INSERT INTO Doctor 
  VALUES(1, 1, 'ABC001', 'Steven Arrow', 'M', 'Bachelor of Medicine  and Surgery, Deakin University, 1980');
  </code></pre>
  
  <p>I keep getting an error:</p>
  
  <blockquote>
    <p>ORA-00001: unique constraint (S3705969.SYS_C001160460) violated</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>