sql - How to add a column and make it a foreign key in single MySQL statement?

Question

In mysql, can I add a column and foreign key in the same statement? And what is the proper syntax for adding the fk?

Here is my SQL:

ALTER TABLE database.table
 ADD COLUMN columnname INT DEFAULT(1),
 FOREIGN KEY (fk_name) REFERENCES reftable(refcolumn) ON DELETE CASCADE;

...and the accompanying error message:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FOREIGN KEY (fk_name) REFERENCES reftable(refcolumn) ON DELETE CASCADE' at line 4

Answer 1

Try this:

ALTER TABLE database.table
  ADD COLUMN columnname INT DEFAULT(1),
  ADD FOREIGN KEY fk_name(fk_column) REFERENCES reftable(refcolumn) ON DELETE CASCADE;