title: date Not null , error ora_01758
body: <p>why I am getting this error ? <br/>
  In the table DDL I only have 2 columns , id (number) and name (varchar)</p>
  <blockquote>
  <p>ALTER TABLE mytable ADD SUSPEND date NOT NULL</p>
  </blockquote>
  <br/>
  <blockquote>
  <p>ORA-01758: table must be empty to add mandatory (NOT NULL) column
  ORA-06512: at line 7</p>
  </blockquote>