LeetCode：196. Delete Duplicate Emails
RojerChen.2018.08.31
今天在解 LeetCode 196. Delete Duplicate Emails 這題，剛好遇到了問題紀錄一下，以下是這題的題目。
Write a SQL query to delete all duplicate email entries in a table named
Person, keeping only unique emails based on its smallest Id.+----+------------------+ | Id | Email | +----+------------------+ | 1 | john@example.com | | 2 | bob@example.com | | 3 | john@example.com | +----+------------------+ Id is the primary key column for this table.
For example, after running your query, the above
Person table should have the following rows:+----+------------------+ | Id | Email | +----+------------------+ | 1 | john@example.com | | 2 | bob@example.com | +----+------------------+
Note:
Your output is the whole
Person table after executing your sql. Use delete statement.