I've got a table, with one of these posts:

ID  |  Data

How you can discover which record has greatest ID?

To obtain the biggest ID:

select max(ID) from myTable

To obtain a record which has the biggest ID:

select *
from MyTable
where ID = (Select max(ID) from myTable)
select max(ID) from tablename
select *
    from YourTable
    where ID = (select max(ID) from YourTable)

In addition to max, you should use TOP on SQL Server

select TOP 1 * from myTable order by id desc

For joint top

select TOP 1 WITH TIES * from myTable order by id desc

Other engines have LIMIT not TOP. This could provide the whol record with no separate MAX sub-query too