Regex solution
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```postgresql []
-- Write your PostgreSQL query statement below
SELECT user_id , email FROM Users
WHERE email ~ '^[a-z,A-Z,0-9,_]+@[a-z,A-Z]+.com
```
```
['PostgreSQL']