Duplicate records - Show records that has same FIRSTNAME & LASTNAME

[Roy Haryanto]

Hi guys,

I am currently facing a problem where I wanna search for duplicate records in the database by firstname & lastname fields.
For the sake of simplicity, let's assume that the firstname and lastname combination is unique to each individual, that means there will be no person with the same firstname& lastname.
My current solution is sloppy at best and it is extremely slow too.
I used PHP to query for each single records (total = 2000+ queries).
e.g. SELECT * FROM users WHERE firstname LIKE $firstname AND lastname LIKE $lastname
This solution is not scalable too. If the userbase grows to the high 5 digits, the system is gonna choke for sure.

Here is the structure of the 'users' table.

user_id | firstname | lastname

Is there any elegant way of solving this problem?

Here is the pseudo code of what I am trying to accomplish.

SELECT * FROM users
WHERE ( number of users which the same firstname & lastname >0 )

Thanks in advance, guys.