text: -- +goose Up
  -- SQL in section 'Up' is executed when this migration is applied
  ALTER TABLE user ADD COLUMN `followed_teacher_at` datetime DEFAULT NULL AFTER `plan_id`;
  UPDATE user SET followed_teacher_at = created_at WHERE followed_teacher_at IS NULL;
  
  -- +goose Down
  -- SQL section 'Down' is executed when this migration is rolled back
  ALTER TABLE user DROP COLUMN `followed_teacher_at`;
  