ALTER TABLE categories
  MODIFY COLUMN api_account_id VARCHAR(36) NULL DEFAULT NULL,
  MODIFY COLUMN provider VARCHAR(64) NULL DEFAULT NULL,
  MODIFY COLUMN external_id VARCHAR(160) NULL,
  MODIFY COLUMN remote_category_id VARCHAR(120) NULL;

ALTER TABLE courses
  MODIFY COLUMN api_account_id VARCHAR(36) NULL DEFAULT NULL,
  MODIFY COLUMN provider VARCHAR(64) NULL DEFAULT NULL,
  MODIFY COLUMN external_id VARCHAR(160) NULL,
  MODIFY COLUMN remote_category_id VARCHAR(120) NULL,
  MODIFY COLUMN remote_course_id VARCHAR(160) NULL;
