What is the SQL for 'next' and 'previous' in a table?

Question

I have a table of items, each of which has a date associated with it. If I have the date associated with one item, how do I query the database with SQL to get the \'previous

Answer 1

Firstly, this should work (the ORDER BY is important):

select min(a)
from theTable
where a > 8

select max(a)
from theTable
where a < 8

For the second question that I begged you to ask...:

    select * 
    from theTable
    where date = 8

    union all

    select *
    from theTable
    where key = (select min(key) 
                 from theTable
                 where key > (select max(key)
                              from theTable
                              where date = 8)
                )

    union all

    select *
    from theTable
    where key = (select max(key) 
                 from theTable
                 where key < (select min(key)
                              from theTable
                              where date = 8)
                )

    order by key