Sql Paging / Sorting - 具有动态排序的高效方法?

时间:2010-03-21 21:42:22

标签: sql pagination

我正在尝试实现这种分页方式:

http://www.4guysfromrolla.com/webtech/042606-1.shtml

CREATE  PROCEDURE [dbo].[usp_PageResults_NAI] 
(
@startRowIndex int,
@maximumRows int
)
AS

DECLARE @first_id int, @startRow int

-- A check can be added to make sure @startRowIndex isn't > count(1)
-- from employees before doing any actual work unless it is guaranteed
-- the caller won't do that

-- Get the first employeeID for our page of records
SET ROWCOUNT @startRowIndex
SELECT @first_id = employeeID FROM employees ORDER BY employeeid

-- Now, set the row count to MaximumRows and get
-- all records >= @first_id
SET ROWCOUNT @maximumRows

SELECT e.*, d.name as DepartmentName 
FROM employees e
INNER JOIN Departments D ON
   e.DepartmentID = d.DepartmentID
WHERE employeeid >= @first_id
ORDER BY e.EmployeeID

SET ROWCOUNT 0

GO 

此方法效果很好,但是,是否可以使用此方法并进行动态字段排序?

如果我们将其更改为

SELECT e.*, d.name as DepartmentName 
FROM employees e
INNER JOIN Departments D ON
   e.DepartmentID = d.DepartmentID
WHERE employeeid >= @first_id
ORDER BY e.FirstName DESC

它打破了排序......

有没有办法将这种分页方法与对不同字段进行排序的能力结合起来?

1 个答案:

答案 0 :(得分:0)

您需要使用此方法跟踪名字和ID。您必须跟踪两者的原因是您的数据集中的名字可能不是唯一的,因此您可以通过它和唯一值进行排序。第一条记录的select中的order by必须与记录集的select中的order by匹配。

未经测试,但你应该明白这一点。您需要将@first_first_name声明为类似于@first_id所做的变量。

DECLARE @first_first_id VARCHAR(50) -- whatever your first name field size is
SET ROWCOUNT @startRowIndex
SELECT @first_id = employeeID, @first_first_name = FirstName FROM employees ORDER BY FirstName DESC, employeeid

SELECT e.*, d.name as DepartmentName 
FROM employees e
INNER JOIN Departments D ON
   e.DepartmentID = d.DepartmentID
WHERE
    e.FirstName <= @first_first_name
    OR (e.FirstName = @first_first_name AND employeeid >= @first_id)
ORDER BY e.FirstName DESC, employeeid