[SQL 문제 풀이] Find Valid Emails (유효한 이메일 찾기)

Can you solve this real interview question? Find Valid Emails - Table: Users +-----------------+---------+ | Column Name | Type | +-----------------+---------+ | user_id | int | | email | varchar | +-----------------+---------+ (user_id) is the unique key for this table. Each row contains a user's unique ID and email address. Write a solution to find all the valid email addresses. A valid email address meets the following criteria: * It contains exactly one @ symbol. * It ends with .com. * The part before the @ symbol contains only alphanumeric characters and underscores. * The part after the @ symbol and before .com contains a domain name that contains only letters. Return the result table ordered by user_id in ascending order.   Example: Input: Users table: +---------+---------------------+ | user_id | email | +---------+---------------------+ | 1 | alice@example.com | | 2 | bob_at_example.com | | 3 | charlie@example.net | | 4 | david@domain.com | | 5 | eve@invalid | +---------+---------------------+ Output: +---------+-------------------+ | user_id | email | +---------+-------------------+ | 1 | alice@example.com | | 4 | david@domain.com | +---------+-------------------+ Explanation: * alice@example.com is valid because it contains one @, alice is alphanumeric, and example.com starts with a letter and ends with .com. * bob_at_example.com is invalid because it contains an underscore instead of an @. * charlie@example.net is invalid because the domain does not end with .com. * david@domain.com is valid because it meets all criteria. * eve@invalid is invalid because the domain does not end with .com. Result table is ordered by user_id in ascending order.