不允许 ASSIGNMENT 语句中包含 FOR XML 子句。

DECLARE @guidList NVARCHAR(max)

SELECT   @guidList=( CAST(OrderGUID AS nvarchar(max)) +',')
FROM OrderWareHouse.dbo.OrderDetail
FOR XML PATH('')
将XML Paht('')查询出来的结果赋值给@guidList 变量此时会出错：不允许 ASSIGNMENT 语句中包含 FOR XML 子句。

修改为：

set @guidList=(SELECT  (CAST(OrderGUID AS nvarchar(max)) +',')
FROM  OrderWareHouse.dbo.OrderDetail
FOR XML PATH(''))

PRINT @guidList