如果您在d列中有一个包含所有可能日期的（可能是临时的）表，您可以

SELECT whatever, d FROM somewhere 
JOIN dates 
WHERE d BETWEEN createdAt AND CURRENT_DATE() 
AND MOD(DATEDIFF(d, createdAt),7)=0

另请参见如何用日期范围填充表？

我会用临时table做这个

DELIMITER //
CREATE PROCEDURE `increment_date_till_now`(
    IN `date_start` DATE,
    IN `day_interval` INT
)
BEGIN
  CREATE TEMPORARY TABLE `__increment_days` (`date` DATE NOT NULL);
  SET @dt = date_start;
  INSERT INTO `__increment_days` VALUES (@dt);
  WHILE (@dt := @dt + INTERVAL day_interval DAY) < CURRENT_DATE() DO
    INSERT INTO `__increment_days` VALUES (@dt);
  END WHILE;
  SELECT * FROM `__increment_days`;
  DROP TABLE `__increment_days`;
END//

然后

CALL increment_date_till_now('2018-01-01', 7);