Question

我使用MSSQL相当新，遇到了一个奇怪的问题。给定上一个查询的第一个记录ID，我需要找到之前的50行，它们符合与第一个查询相同的条件，并按降序返回。这是一个ASP.NET站点，我很确定ASP方面是正确的但是当我尝试运行SQL查询时它会给出错误的结果

这是我一直在尝试的SQL

 WITH PreviousPosts AS 
 (
    SELECT *
    FROM [database].[dbo].[table]
    WHERE (A_1STNAME LIKE '(variable)%')
    AND A_RECID < '(lastPost)'
 )
SELECT TOP 50 * FROM PreviousPosts
ORDER BY A_RECID ASC

其中“（变量）”和“（lastPost）”实际上用我的C＃填充了正确的参数

我不再收到错误，但现在无论作为lastPost提供什么，我都会得到相同的结果。

更新：结果是表格中第一个有第一个名字的50个（在我的测试用例中）“詹姆斯”

感谢任何帮助:)

Answer 1

您错过了CTE中的表名。见**[TABLENAME]**

 WITH PreviousPosts AS 
 (
    SELECT *
    FROM [database].[dbo].**[TABLENAME]**
    WHERE (A_1STNAME LIKE (variable)%)
    AND A_RECID < (lastPost)
    ORDER BY A_RECID DESC
 )
SELECT TOP 50 * FROM PreviousPosts
ORDER BY A_RECID ASC

Answer 2

如前所述，您错过了CTE中的表名。您还想知道您想从CTE中选择哪些列。

你应该改变：

SELECT TOP 50 FROM PreviousPosts ORDER BY A_RECID ASC

为：

SELECT TOP 50 * FROM PreviousPosts ORDER BY A_RECID ASC

Answer 3

要添加到列表中，您无法在CTE中进行订购。为了得到你想要的东西，完全抛弃CTE：

SELECT top 50 * 
FROM [database].[dbo].**[TABLENAME]** 
WHERE (A_1STNAME LIKE (variable)%) 
AND A_RECID < (lastPost) 
ORDER BY A_RECID DESC

Answer 4

这是一次尝试，我现在知道你的架构了。我仍然需要做出比我更舒服的假设，所以这可能不是正确的：

;WITH RankedRecords AS
(
    SELECT
        ROW_NUMBER() OVER(ORDER BY A_RECID DESC) Row
        , A_RECID
    FROM [database]..[table]
    WHERE A_1STNAME LIKE '(variable)%')
        AND CAST(LEFT(A_RECID, 8) AS DATE) < CAST(LEFT('(lastPost)', 8) AS DATE)
)
SELECT TOP 50
    T.*
FROM[database]..[table] T
INNER JOIN RankedRecords
    ON RankedRecords.A_RECID = T.A_RECID
    AND RankedRecords BETWEEN (@LastPost - 51) AND (@LastPost - 1)
ORDER BY RankedRecords.Row

选择50个前一行

4 个答案: