# \#196 Delete Duplicate Emails
## *刪除tabl中重複的email(保留id最小者)*
## Log
- build 20210422 by syhuang

## xxx
- xxx

## 較易理解的解法
- group搭配min, 用not in排除刪除範圍外, 注意因為要異動同個table, 因此用這個方法要"鏡像"(t)

delete from Person where id not in(
select t.id from(
    select min(p.id) id from Person p group by p.email
)t)

## 備註
## 參考
- https://leetcode.com/problems/delete-duplicate-emails/discuss/55614/A-skillful-mysql-solution-avoid-%22-select-and-update-conflict%22
###### tags: `leetcode`, `leetcode-easy`, `sql`