Count distinct value pairs in multiple columns in SQL

Question

What query will count the number of rows, but distinct by three parameters?

Example:

Id      Name        Address 
==============================
1     My         


        

Answer 1

Another (probably not production-ready or recommended) method I just came up with is to concat the values to a string and count this string distinctively:

SELECT count(DISTINCT concat(id, name, address)) FROM mytable;