Find Duplicate Data

1. how to find a duplicate records from table?
Lets the table name is report and its have a two field, id and type.
type contain a numbers of duplicate records...

first retrieve the all records from table:
select type,id from report;

type	id
php	1
php	2
mysql	3
mysql	4
lamp	5
lamp	6

use command:
select count(type), id from report group by type having count(type)>1;

get the records like this:

count(type)	id
2	1
2	2
2	3

the above table explains the id 1,2,3 contain the 2 number of duplicates data.