如何获取单独数据集中 cte 的行计数？

我已经找到了一种使用 CTE 和 Row_Number 函数从数据库获取快速分页结果的方法，如下所示......

DECLARE @PageSize INT = 1
DECLARE @PageNumber INT = 2

DECLARE @Customer TABLE (
  ID       INT IDENTITY(1, 1),
  Name     VARCHAR(10),
  age      INT,
  employed BIT)

INSERT INTO @Customer
    (name,age,employed)
SELECT 'bob',21,1
    UNION ALL
SELECT 'fred',33,1
    UNION ALL
SELECT 'joe',29,1
    UNION ALL
SELECT 'sam',16,1
    UNION ALL
SELECT 'arthur',17,0;


WITH cteCustomers
     AS ( SELECT
            id,
            Row_Number( ) OVER(ORDER BY Age DESC) AS Row
          FROM   @Customer
          WHERE  employed = 1 
     /*Imagine I've joined to loads more tables with a really complex where clause*/
     )       

SELECT
  name,
  age,
  Total = ( SELECT
              Count( id )
            FROM   cteCustomers )
FROM       cteCustomers
INNER JOIN @Customer cust
  /*This is where I choose the columns I want to read, it returns really fast!*/
  ON cust.id = cteCustomers.id
WHERE      row BETWEEN ( @PageSize * @PageNumber - 1 ) AND ( @PageSize * ( @PageNumber ) )
ORDER      BY row ASC

使用这种技术，即使在复杂的连接和过滤器上，返回的结果也非常非常快。

要执行分页，我需要知道完整 CTE 返回的总行数。我通过放置一个容纳它的柱子来“固定”它

Total = ( SELECT
              Count( id )
            FROM   cteCustomers )

有没有更好的方法来返回不同结果集中的总计而不将其合并到列中？因为它是 CTE，所以我似乎无法将其放入第二个结果集中。

如果不首先使用临时表，我会使用 CROSS JOIN 来降低对 COUNT 进行逐行评估的风险

要获得总行数，这需要单独发生在 WHERE 中

WITH cteCustomers
     AS ( SELECT
            id,
            Row_Number( ) OVER(ORDER BY Age DESC) AS Row
          FROM   @Customer
          WHERE  employed = 1 
     /*Imagine I've joined to loads more tables with a really complex where clause*/
     )       

SELECT
  name,
  age,
  Total
FROM       cteCustomers
INNER JOIN @Customer cust
  /*This is where I choose the columns I want to read, it returns really fast!*/
  ON cust.id = cteCustomers.id

CROSS JOIN

(SELECT Count( *) AS Total FROM   cteCustomers ) foo

WHERE      row BETWEEN ( @PageSize * @PageNumber - 1 ) AND ( @PageSize * ( @PageNumber ) )
ORDER      BY row ASC

但是，这并不能保证给出准确的结果，如此处所示：
我可以从 sql server 中的一个 sql 查询中获取 count() 和行吗？ https://stackoverflow.com/q/2798094/27535

编辑：经过一些评论。

如何避免交叉连接

WITH cteCustomers
     AS ( SELECT
            id,
            Row_Number( ) OVER(ORDER BY Age DESC) AS Row,
            COUNT(*) OVER () AS Total --the magic for this edit
          FROM   @Customer
          WHERE  employed = 1 
     /*Imagine I've joined to loads more tables with a really complex where clause*/
     )       

SELECT
  name,
  age,
  Total
FROM       cteCustomers
INNER JOIN @Customer cust
  /*This is where I choose the columns I want to read, it returns really fast!*/
  ON cust.id = cteCustomers.id
WHERE      row BETWEEN ( @PageSize * @PageNumber - 1 ) AND ( @PageSize * ( @PageNumber ) )
ORDER      BY row ASC

注意：YMMV 的性能取决于 2005 年或 2008 年、服务包等

Edit 2:

SQL Server 中心 http://www.sqlservercentral.com/articles/T-SQL/66030/显示了另一种具有反向 ROW_NUMBER 的技术。看起来很有用