查询结果集如果记录数比较多时，服务器内存和浏览器内存都可能溢出，另外，数据量太大客户端的性能会降低，滚动条较小，操作也不方便，需要数据库分页查询。
SQL Server分页：
select top #pageSize# * from students where id not in
(select top #pageSize# * (#pageNumber#-1) id from students order by id) order by id
My SQL分页：
select * from students order by id limit #pageSize#*(#pageNumber#-1),#pageSize#
Oracle分页：
SELECT * FROM
(
SELECT T1.*
FROM
(
SELECT T.*, ROWNUM RN FROM TR_ORDER T ORDER BY T.ORDER_ID DESC
) T1
WHERE
T1.RN<=#{pageSize} * #{pageNumber}
) T
WHERE T.RN>#{pageSize}*(#{pageNumber}-1)
