title: What is the correct syntax for Firebird's default constraint?
body: <pre><code>create table students (
    tnum char(9) PRIMARY KEY CHECK (tnum SIMILAR TO 'T[:DIGIT:]{8}'),
    ssn varchar(9) UNIQUE NOT NULL CHECK (ssn SIMILAR TO '[:DIGIT:]{9}'),
    first_name varchar(20) NOT NULL,
    credits numeric(3, 0) NOT NULL DEFAULT 0
  );
  </code></pre>
  
  <p>Why is this not working? If I remove the "default 0", it works but if I leave the "default 0" in it doesn't work. So what is the correct syntax for the default constraint?</p>