Question

I’m trying to import product data from different sellers, the data is imported to an import table with the following fields:
id=auto increment
sellerid=key to seller
sellerproductid=the product id a seller gives to a product
lastupdate=the date that this item is updated

So seller A can have Product id 22 witch is the same product as seller B having product id 55.

When seller A changes the price of product A there will be a line in the import. I currently have many “historical” lines and am only interested in getting the most current of the import

For example:

1  A   22     2012 01 22
2  A   22     2012 05 10
44 A   22     2012 11 10

I would like to archive the first 2 lines like so:

insert into archive ....
values ( select * from import where id in(
 select id from import 
 where `lastupdate` < max(`lastupdate`)
 group by sellerid, sellerproductid
)

I’m having trouble finding the right mysql statement to get the id’s of the older records.

Answer 1

This should give all but latest entry :

SELECT distinct t1.* 
FROM import t1 inner join import t2 
on t1.sellerid = t2.sellerid and t1.sellerproductid = t2.sellerproductid 
where t1.lastupdate < t2.lastupdate;