When defining a column, it's possible to indicate that it's the primary key, like this:
This is convenient but can be hazardous, because if there's a problem with the creation of the constraint, you are left with a part-done change for that database and will need to manually roll it back. You might prefer to create the primary key constraint in a separate change.
This rule will fail if a
primaryKey attribute is found on a
<constraints> tag when adding a column.
No extra options.