196. Delete Duplicate Emails

Description

Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id.

Note:

Your output is the whole Person table after executing your sql. Use delete statement.

Constraints

Approach

Links

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Examples

Example 1

Input:

Id	Email
1	[e-mail]
2	[e-mail]
3	[e-mail]

Id is the primary key column for this table.

Output:

Id	Email
1	[e-mail]
2	[e-mail]

Solutions

Solution 1

# MySQL query statement

DELETE p1 
FROM Person p1, Person p2
WHERE p1.Email = P2.Email AND p1.Id > p2.Id

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