<h2><a href="https://leetcode.com/problems/find-users-with-valid-e-mails/?envType=study-plan-v2&envId=top-sql-50">1664. Find Users With Valid E-Mails</a></h2><h3>Easy</h3><hr><p>Table: <code>Users</code></p>

<pre>

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

| Column Name | Type |

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

| user_id | int |

| name | varchar |

| mail | varchar |

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

user_id is the primary key (column with unique values) for this table.

This table contains information of the users signed up in a website. Some e-mails are invalid.

</pre>

<p>&nbsp;</p>

<p>Write a solution to find the users who have <strong>valid emails</strong>.</p>

<p>A valid e-mail has a prefix name and a domain where:</p>

<ul>

<li><strong>The prefix name</strong> is a string that may contain letters (upper or lower case), digits, underscore <code>&#39;_&#39;</code>, period <code>&#39;.&#39;</code>, and/or dash <code>&#39;-&#39;</code>. The prefix name <strong>must</strong> start with a letter.</li>

<li><strong>The domain</strong> is <code>&#39;@leetcode.com&#39;</code>.</li>

</ul>

<p>Return the result table in <strong>any order</strong>.</p>

<p>The result format is in the following example.</p>

<p>&nbsp;</p>

<p><strong class="example">Example 1:</strong></p>

<pre>

<strong>Input:</strong>

Users table:

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

| user_id | name | mail |

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

| 1 | Winston | [email protected] |

| 2 | Jonathan | jonathanisgreat |

| 3 | Annabelle | [email protected] |

| 4 | Sally | [email protected] |

| 5 | Marwan | quarz#[email protected] |

| 6 | David | [email protected] |

| 7 | Shapiro | [email protected] |

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

<strong>Output:</strong>

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

| user_id | name | mail |

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

| 1 | Winston | [email protected] |

| 3 | Annabelle | [email protected] |

| 4 | Sally | [email protected] |

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

<strong>Explanation:</strong>

The mail of user 2 does not have a domain.

The mail of user 5 has the # sign which is not allowed.

The mail of user 6 does not have the leetcode domain.

The mail of user 7 starts with a period.

</pre>