Mysql查询某字段重复值并删除重复值
时间：2022-03-15 15:13
1.查询重复值：
select code,count(*) as count from hospital group by code having count>1;
该语句查询code重复值大于1的记录
2.删除重复：
DELETE FROM hospital
WHERE
id NOT IN (SELECT
dt.minno
FROM
(SELECT
MIN(id) AS minno
FROM
hospital
GROUP BY code) dt);
该语句保留id最小的记录，其余code重复的记录全部删除
