Column <str> is specified more than once in the column list of a
  constraint.

  Explanation:  You specified the same column more than once in
  the column list of a UNIQUE, PRIMARY KEY or FOREIGN KEY
  constraint.  Alternatively, you specified the column in more
  than one NOT NULL constraint.

  User Action:  Specify each column only once.  Check the CREATE
  or ALTER TABLE command and remove the redundant reference.