1517. Find Users With Valid E-Mails

https://leetcode.com/problems/find-users-with-valid-e-mails

Description

Table: Users

+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| user\_id       | int     |
| name          | varchar |
| mail          | varchar |
+---------------+---------+
user\_id is the primary key for this table.
This table contains information of the users signed up in a website. Some e-mails are invalid.

Write an SQL query to find the users who have valid emails.

A valid e-mail has a prefix name and a domain where:

• The prefix name is a string that may contain letters (upper or lower case), digits, underscore '_', period '.' and/or dash '-'. The prefix name must start with a letter.

• The domain is '@leetcode.com'.

Return the result table in any order.

The query result format is in the following example.

Users
+---------+-----------+-------------------------+
| user\_id | name      | mail                    |
+---------+-----------+-------------------------+
| 1       | Winston   | [e-mail]    |
| 2       | Jonathan  | jonathanisgreat         |
| 3       | Annabelle | [e-mail]     |
| 4       | Sally     | [e-mail] |
| 5       | Marwan    | quarz#[e-mail] |
| 6       | David     | [e-mail]       |
| 7       | Shapiro   | [e-mail]     |
+---------+-----------+-------------------------+
Result table:
+---------+-----------+-------------------------+
| user\_id | name      | mail                    |
+---------+-----------+-------------------------+
| 1       | Winston   | [e-mail]    |
| 3       | Annabelle | [e-mail]     |
| 4       | Sally     | [e-mail] |
+---------+-----------+-------------------------+
The mail of user 2 doesn't have a domain.
The mail of user 5 has # sign which is not allowed.
The mail of user 6 doesn't have leetcode domain.
The mail of user 7 starts with a period.

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