Question

I have 2 tables in mysql db

T1 : registration
T2 : multiple_email

and I have a field email_id in both the tables. I want to run a query to see if a email is valid. So, I can run 2 queries as

select count(*) from registration where emailid = $emailid
select count(*) from multiple_email where emailid = $emailid 

and if one of the count is greater than 0, I consider it as a valid email.

Is there an elegant way of doing it in single query?

Answer 1

select count(*) + 
(select count(*) from multiple_email where emailid = $emailid)
from registration where emailid = $emailid