无法评估抛出错误表达式的 SSIS 表达式生成器中的动态查询答案

【问题标题】：Dynamic query in SSIS expression builder throwing an error expression cannot be evaluated无法评估抛出错误表达式的 SSIS 表达式生成器中的动态查询
【发布时间】：2023-02-17 23:10:50
【问题描述】：

我正在编写一个示例来编写动态 sql 以在 ssis 表达式生成器中转换数据。它无法评估表达式。下面是动态查询：

 DECLARE @Cols as NVARCHAR(MAX)
 DECLARE @SQL as NVARCHAR(MAX)
 
SELECT @Cols = COALESCE(@Cols + ', ','') + QUOTENAME(Name)
FROM
   (
     SELECT DISTINCT Category
     FROM Product
   ) As t1

SET @SQL = 'SELECT *
FROM
(
    SELECT ProductID,
    Category,
    Quantity
    FROM   Product
) as PivotData
PIVOT
(
   COUNT(Quantity)
   FOR Category IN (" + @Cols + ")
) AS PivotResult'

【问题讨论】：

标签： ssis dynamic-sql expressionbuilder

【解决方案1】：

我认为 + @Cols 周围的双引号需要是单引号，见下文。

DECLARE @Cols as NVARCHAR(MAX)
 DECLARE @SQL as NVARCHAR(MAX)
 
SELECT @Cols = COALESCE(@Cols + ', ','') + QUOTENAME(Name)
FROM
   (
     SELECT DISTINCT Category
     FROM Product
   ) As t1

SET @SQL = 'SELECT *
FROM
(
    SELECT ProductID,
    Category,
    Quantity
    FROM   Product
) as PivotData
PIVOT
(
   COUNT(Quantity)
   FOR Category IN (' + @Cols + ')
) AS PivotResult'

【讨论】：