Find Duplicate Emails

SQL coding challenge · Difficulty: easy · +50 XP

Table: users

+-------+---------+

| Column | Type   |

+-------+---------+

| id    | INT     |
| name  | VARCHAR |
| email | VARCHAR |

+-------+---------+

Primary key: id

email is NOT guaranteed to be unique.

Problem

-------

Find all email addresses that appear more

than once in the users table.

Return: email, count

Order: email ASC

Example Input

-------------

+----+-------+-------------------+

| id | name  | email             |

+----+-------+-------------------+

|  1 | Alice | alice@example.com |
|  2 | Bob   | bob@example.com   |
|  3 | Carol | alice@example.com |
|  4 | Dave  | dave@example.com  |
|  5 | Eve   | bob@example.com   |

+----+-------+-------------------+

Expected Output

---------------

+-------------------+-------+

| email             | count |

+-------------------+-------+

| alice@example.com |     2 |
| bob@example.com   |     2 |

+-------------------+-------+

Hints

-----

• GROUP BY email groups rows with same email
• HAVING COUNT(*) > 1 filters to duplicates only