Easy

Nr	Difficulty	Title	Link
196	Easy	Delete Duplicate Emails	https://leetcode.com/problems/delete-duplicate-emails/description/?envType=study-plan-v2&envId=top-sql-50
197	Easy	Rising Temperature	https://leetcode.com/problems/rising-temperature/description/
577	Easy	Employee Bonus	https://leetcode.com/problems/employee-bonus/description/?envType=study-plan-v2&envId=top-sql-50
584	Easy	Find Customer Referee	https://leetcode.com/problems/find-customer-referee/description/
619	Easy	Biggest Single Number	https://leetcode.com/problems/biggest-single-number/submissions/?envType=study-plan-v2&envId=top-sql-50
1075	Easy	Project Employees I	https://leetcode.com/problems/project-employees-i/submissions/?envType=study-plan-v2&envId=top-sql-50
1141	Easy	User Activity for the Past 30 Days I	https://leetcode.com/problems/user-activity-for-the-past-30-days-i/description/?envType=study-plan-v2&envId=top-sql-50
1251	Easy	Average Selling Price	https://leetcode.com/problems/average-selling-price/description/?envType=study-plan-v2&envId=top-sql-50
1280	Easy	Students and Examinations	https://leetcode.com/problems/students-and-examinations/description/?envType=study-plan-v2&envId=top-sql-50
1484	Easy	Group Sold Products By The Date	https://leetcode.com/problems/group-sold-products-by-the-date/description/?envType=study-plan-v2&envId=top-sql-50
1517	Easy	Find Users With Valid E-Mails	https://leetcode.com/problems/find-users-with-valid-e-mails/description/?envType=study-plan-v2&envId=top-sql-50
1527	Easy	Patients With a Condition	https://leetcode.com/problems/patients-with-a-condition/description/?envType=study-plan-v2&envId=top-sql-50
1633	Easy	Percentage of Users Attended a Contest	https://leetcode.com/problems/percentage-of-users-attended-a-contest/?envType=study-plan-v2&envId=top-sql-50
1667	Easy	Fix Names in a Table	https://leetcode.com/problems/fix-names-in-a-table/description/?envType=study-plan-v2&envId=top-sql-50
1789	Easy	Primary Department for Each Employee	https://leetcode.com/problems/primary-department-for-each-employee/description/?envType=study-plan-v2&envId=top-sql-50
1978	Easy	Employees Whose Manager Left the Company	https://leetcode.com/problems/employees-whose-manager-left-the-company/description/?envType=study-plan-v2&envId=top-sql-50

Questions

196. Delete Duplicate Emails

Table: Person

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| email       | varchar |
+-------------+---------+
id is the primary key (column with unique values) for this table.
Each row of this table contains an email. The emails will not contain uppercase letters.

Write a solution to delete all duplicate emails, keeping only one unique email with the smallest id.

Example 1:
Input: 
Person table:
+----+------------------+
| id | email            |
+----+------------------+
| 1  | [e-mail] |
| 2  | [e-mail]  |
| 3  | [e-mail] |
+----+------------------+
Output: 
+----+------------------+
| id | email            |
+----+------------------+
| 1  | [e-mail] |
| 2  | [e-mail]  |
+----+------------------+
Explanation: [e-mail] is repeated two times. We keep the row with the smallest 
Id = 1.

DELETE p1.* FROM person p1, person p2
WHERE p1.email = p2.email 
    AND p1.id > p2.id