Question

在article here的帮助下以及SO专家最近的回答中，我得到了以下内容，这将有助于我有效地翻阅一组记录。

我认为我的最后几个问题是

了解我最后如何在有效负载中包含Total Number of Records SQL CTE称为“总计”。这是你怎么做的？
还有其他建议吗？更简洁或改进的潜在领域？ Return Total Number of Pages

DECLARE @page_size INT = 5;
DECLARE @page_nbr INT = 4;
DECLARE @search NVARCHAR(MAX) = '';
DECLARE @sort_order INT = 2;

WITH AllProducts
AS
(
SELECT *, 
CASE @sort_order
    WHEN 1 THEN ROW_NUMBER() OVER ( ORDER BY ProductID )
    WHEN 2 THEN ROW_NUMBER() OVER ( ORDER BY ProductName )
END AS 'Seq'    
FROM Products
),
Filtered
AS
(
SELECT * FROM AllProducts
WHERE ProductName like '%'+@search+'%'
OR
@search is null
)
SELECT (select COUNT(*) from Filtered) as 'Total', * FROM Filtered
WHERE seq > (@page_nbr - 1) * @page_size
  AND seq <= @page_nbr * @page_size

Answer 1

我认为您的查询有问题：它会记录（用于分页），然后应用过滤器。

例如，您可以请求记录的第2页，但同时可以过滤掉所有具有相应seq值的记录。因此，在这种情况下，查询不会产生任何结果，尽管表中可能有大量记录。

为了解决这个问题，你可以在同一个CTE中进行过滤和记录编号，如下所示：

DECLARE @page_size INT = 5;
DECLARE @page_nbr INT = 4;
DECLARE @search NVARCHAR(MAX) = '';
DECLARE @sort_order INT = 2;

WITH Filtered AS (
    SELECT *, 
        CASE @sort_order
            WHEN 1 THEN ROW_NUMBER() OVER ( ORDER BY ProductID )
            WHEN 2 THEN ROW_NUMBER() OVER ( ORDER BY ProductName )
        END AS 'Seq'
    FROM AllProducts
    WHERE ProductName like '%'+@search+'%' OR @search is null
)
SELECT (select COUNT(*) from Filtered) as 'Total', * FROM Filtered
WHERE seq > (@page_nbr - 1) * @page_size
  AND seq <= @page_nbr * @page_size

在cte中返回总记录

1 个答案: