A small problem with Oracle's paging query

Order form with the same order ID as the Order Information table (multiple order information columns)

Find out all orders and their information and page by order

SELECT * FROM (Select a. *, (Dense_rank () over (order by ID DESC)) as Numindex from (select O. *, Dense_rank () over (order B Y o.id DESC) as RN from Order O) a where RN <=) where Numindex > 0

Find out all orders and their information and page by order information

SELECT * FROM (select A.*, ROWNUM RN from (SELECT * from Order o left  joins OrderDetail od on O.id=od.orderid) A wher E ROWNUM <=) WHERE RN >= 0

Rank () Over,dense_rank (), the difference between row_number ()

Rank () Over is the function of finding a rank after the specified condition is detected, but there is a feature. If it is the student rankings, then practical this function, the results of the same two are tied, for example 1 2 2 4.

Dense_rank () The Role and rank () very much like, the only difference is that brought life student's results tied up, the next classmate does not empty the rank of the side, for example, 1 2 2 3.

Row_number () is not the same, and the difference between it and the above is very obvious, this function does not need to consider whether to tie, even if the value of the query based on the same values will continue to rank, such as

The usage of rank () Over,dense_rank (), Row_number () is detailed http://www.cnblogs.com/wuyisky/archive/2010/02/24/oracle_rank.html

A small problem with Oracle's paging query