leetcode_sql_4,196

930 단어
196. Delete Duplicate Emails
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  | [email protected] |
| 2  | [email protected]  |
| 3  | [email protected] |
+----+------------------+
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  | [email protected] |
| 2  | [email protected]  |
+----+------------------+

 
# Write your MySQL query statement belowDELETE PFROM Person P,Person P1WHERE P.Id>P1.Id AND P.Email=P1.Email;
 
 
다음으로 전송:https://www.cnblogs.com/coskaka/p/7137461.html

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