SQL Return 子查询 'Total Records' 到外部查询

Question

这个让我有点难过，我试图从这个 SQL 查询中获取我的顶级（根）节点 XML 中的总计数：

    SELECT COUNT(*) OVER() as '@totalCount', (
        SELECT COUNT(*) OVER() as totalCount, [Title], [Year], [Type], [Poster]
        FROM movies As result where CONTAINS(Title, @Title) Order by [Weight] DESC
        OFFSET ((@PageNumber - 1) * @RowspPage) ROWS
        FETCH NEXT @RowspPage ROWS ONLY
        FOR XML AUTO, type
    ) 
    FOR XML PATH('root')

显然 COUNT(*) OVER() 只返回“1”，因为它是在顶层执行的，而不是在子查询中。但我只想在根节点中显示一次，而不是对每个结果重复。

如有任何帮助，我们将不胜感激。

Answer 1

编辑：这里是一个包含通用数据的工作示例：

;with myCTE as
(
    select *
    from sys.objects
)
select (select count(*) from myCTE) as [@Counter]
    ,(
       SELECT myCTE.object_id AS id
             ,mycte.name AS name 
       from myCTE
       for xml path('object'),TYPE
      )       
for xml path('test')

您可能会尝试将您的查询转移到 CTE 中并将其放入如下内容：

;WITH MyQueryAsCTE AS
(
    SELECT [Title], [Year], [Type], [Poster]
    FROM movies As result where CONTAINS(Title, @Title) Order by [Weight] DESC
    OFFSET ((@PageNumber - 1) * @RowspPage) ROWS
    FETCH NEXT @RowspPage ROWS ONLY
)
SELECT  (SELECT Count(*) FROM MyQueryAsCTE) as '@totalFound'
       ,[Title] AS [Movie/Title] 
       ,[Year] AS [Movie/Year]
       ,[Type] AS [Movie/Type]
       ,[Poster] AS [Movie/Poster]
FROM MyQueryAsCTE
FOR XML PATH('root')

Answer 2

有趣的字符串...这是一个完全的 hack，但它有效：

DECLARE @totalCount AS INT
DECLARE @result varchar(MAX)

SELECT @totalCount = COUNT(*) OVER(), @result = COALESCE(@result + '', '') + '<result title="' + [Title] + '" year="' + [Year] + '" type="' + [Type] + '"/>'
FROM Movies where CONTAINS(Title, '@Title') Order by [Weight] DESC
OFFSET ((@PageNumber - 1) * @RowspPage) ROWS
FETCH NEXT @RowspPage ROWS ONLY
SELECT '<root totalCount="' + CAST(@totalCount AS VARCHAR) + '">' + @result + '</root>'

输出：

似乎有一个 faster/more 高效的执行计划，因为只进行一次计算，不需要对任何表进行额外查询。

SQL Return 子查询 'Total Records' 到外部查询

SQL Return subquery 'Total Records' to outer query

xml

sql

subquery

sql-server-2008