code: function onFetching(model, columns, options) {
          if (options.forUpdate && options.transacting) {
              options.query.forUpdate();
          }
      }
docs: http://knexjs.org/#Builder-forUpdate
  https://dev.mysql.com/doc/refman/5.7/en/innodb-locking-reads.html
  
  Lock target collection/model for further update operations.
  This avoids collisions and possible content override cases.