How to select domain name from email address

Question

I have email addresses like [email protected], [email protected] [email protected] ... etc. I want a Mysql SELECT that will trim user names and .com and return output as gmail,ymail,hotmail, etc.

Answer 1

Assuming that the domain is a single word domain like gmail.com, yahoo.com, use

select (SUBSTRING_INDEX(SUBSTR(email, INSTR(email, '@') + 1),'.',1)) 

The inner SUBSTR gets the right part of the email address after @ and the outer SUBSTRING_INDEX will cut off the result at the first period.

otherwise if domain is expected to contain multiple words like mail.yahoo.com, etc, use:

select (SUBSTR(email, INSTR(email, '@') + 1, LENGTH(email) - (INSTR(email, '@') + 1) - LENGTH(SUBSTRING_INDEX(email,'.',-1))))  

LENGTH(email) - (INSTR(email, '@') + 1) - LENGTH(SUBSTRING_INDEX(email,'.',-1)) will get the length of the domain minus the TLD (.com, .biz etc. part) by using SUBSTRING_INDEX with a negative count which will calculate from right to left.

Answer 2

I prefer:

select right(email_address, length(email_address)-INSTR(email_address, '@')) ... 

so you don't have to guess how many sub-domains your user's email domain has.