DELETE
FROM
klinesbases
WHERE
id NOT IN (
SELECT
dt.minno
FROM
(
SELECT
MIN(id) AS minno
FROM
klinesbases
GROUP BY
start_time,symbol,type
) dt
)
根据
start_time,symbol,type 分组,查找出id最小的。然后再查找id不包含刚才查出来的。这样就查询出了所有的重复数据(除了id最小的那行)