MySQL Query to Count Unique Domains from Email Address field

Question

I'd like to get a better idea of what domains my customers are using. I could easily do this in PHP by explodeing each address and counting the domain that way. But I'm wondering if there's a way to get this information with just a plain MySQL query?

This is what sample output would look like:

gmail.com | 3942

yahoo.com | 3852

hotmail.com | 209

... and so on, where the first column is the email addresses domain, and the 2nd column is the number of addresses at that domain.

Answer 1

You would have to do something like this:

SELECT substring_index(email, '@', -1) domain, COUNT(*) email_count
FROM table
GROUP BY substring_index(email, '@', -1)

-- If you want to sort as well:
ORDER BY email_count DESC, domain;

Answer 2

Adding ORDER BY to WoLpH's answer makes the output more clear:

SELECT substring_index(email, '@', -1), COUNT(*) AS MyCount
FROM `database`.`table`
GROUP BY substring_index(email, '@', -1)
ORDER BY MyCount DESC;

Answer 3

Small tweak to Wolph's original above to shorten a bit and add nice column name and limit results in case list is long. Adjust limit to your own liking

select substring_index(email, '@', -1) AS domain, count(*) from TABLE group by domain order by count(*) DESC limit 40;