Question

This shows me all the first names and last names that have exactly two entries that are identical

SELECT `firstname`,`lastname`,COUNT(*) AS Count 
FROM `people` 
GROUP BY `firstname`,`lastname`
HAVING Count = 2

How do I turn this into a DELETE FROM WHERE statement with a LIMIT to only remove one of each of the entries and leave the other one.

okay this appears to be way to technical i’m just going to do it in a php while loop

Answer 1

You can create a table with 1 record of each of the duplicates: Then delete all the dup records from the people table and then re-insert the dup records.

-- Setup for example
create table people (fname varchar(10), lname varchar(10));

insert into people values ('Bob', 'Newhart');
insert into people values ('Bob', 'Newhart');
insert into people values ('Bill', 'Cosby');
insert into people values ('Jim', 'Gaffigan');
insert into people values ('Jim', 'Gaffigan');
insert into people values ('Adam', 'Sandler');

-- Show table with duplicates
select * from people;

-- Create table with one version of each duplicate record
create table dups as 
    select distinct fname, lname, count(*) 
    from people group by fname, lname 
    having count(*) > 1;

-- Delete all matching duplicate records
delete people from people inner join dups 
on people.fname = dups.fname AND 
   people.lname = dups.lname;

-- Insert single record of each dup back into table
insert into people select fname, lname from dups;

-- Show Fixed table
select * from people;