Question

I have email addresses like [e-mail], [e-mail] [e-mail] … 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.