Question

I have a table like this

id  type        type_id cust    ip_address      datetime
395 Category    5       0       119.63.196.29   2012-11-27 00:34:21
394 Cart        812     0       84.208.217.178  2012-11-27 00:31:48
393 Cart        812     0       84.208.217.178  2012-11-27 00:31:41
392 Cart        812     0       84.208.217.178  2012-11-27 00:31:35
391 Product     812     0       84.208.217.178  2012-11-27 00:31:34

i want to select 4 rows, ordered by id desc, which have distinct type+type_id data.

so the result from the query would remove id 393 and 392, because type and type_id combination is already in id 394.

pseudocode: select * from table where type and type_id is distinct from resultset, order by id desc limit 4

Answer 1

select * from table
where id in 
(
  select min(id)
  from table 
  group by  type, type_id 
)
order by id desc
limit 4