title: How to change the foreign key referential action? (behavior)
body: <p>I have set up a table that contains a column with a foreign key, set to <code>ON DELETE CASCADE</code> (delete child when parent is deleted) </p>
  
  <p>What  would the SQL command be to change this to <code>ON DELETE RESTRICT</code>? (can't delete parent if it has children)</p>