SQL Server 2005增加了不少新特性,其中NTILE和ROW_NUMER使得我们不再为SQL如何灵活方便的分页伤脑筋了(不必再羡慕Oracle等数据库了)。
下面就是一个很简单的分页查询语句:
DECLARE @rows_per_page AS INTEGER
DECLARE @current_page AS INTEGER
DECLARE @total_pages AS INTEGER
-- 设置每页的行数
SET @rows_per_page = 20
-- 设置要显示的页号(从1开始)
SET @current_page = 2
-- 计算总页数
SELECT @total_pages = COUNT(*) / @rows_per_page
FROM testtable;
-- 列出指定页的内容
WITH t AS
(
SELECT NTILE(@total_pages) OVER(ORDER BY id) AS page_number, *
FROM testtable
)
SELECT * from t
WHERE page_number = @current_page
程序简单到可以不用说明的程度。
我们可以利用上述简单的语句,变化排序条件和查询表,就可以做出一个很通用的分页查询的存储过程或查询语句了。
同样的,使用ROW_NUMBER也可以做到分页查询:
DECLARE @rows_per_page AS INTEGER
DECLARE @current_page AS INTEGER
DECLARE @start_row_num AS INTEGER
-- 设置每页的行数
SET @rows_per_page = 20
-- 设置要显示的页号(从1开始)
SET @current_page = 2
-- 设置开始行号
SET @start_row_num = (@current_page - 1) * @rows_per_page
WITH t AS
(
SELECT ROW_NUMBER() OVER(ORDER BY id) AS row_number, *
FROM testtable
)
SELECT * from t
WHERE row_number BETWEEN @start_row_num AND @start_row_num + @rows_per_page 似乎更简单的样子。
至于哪种效率更高,这需要大家实际测试了。