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LeetCode:196. 删除重复的电子邮箱
2022-07-22 09:11:00 【东西方集大成者】
这个题很妙啊https://leetcode-cn.com/problems/delete-duplicate-emails/
官方题解:
DELETE p1 FROM Person p1,
Person p2
WHERE
p1.Email = p2.Email AND p1.Id > p2.Id;
注意:
1,delete 语句中有两个表的时候,要删除记录的表位于delete和from之间,并且需要表别名
2,以p1的Email去连结p2的Email作为关联键,并且直接比较Id的大小,p2.Id一直是数值最小的Id,p1表的行会不断减少,而p2表不会。
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