Question

我只想通过“Age_Band”分组进行简单查询。并设置参数以帮助我轻松更改分组列。但是得到了一个错误： “每个GROUP BY表达式必须包含至少一个不是外部引用的列。”

如何使用参数时出错？非常感谢

DECLARE @group nvarchar(50);  
DECLARE @SQLString nvarchar(500);  
DECLARE @ParmDefinition nvarchar(500);  
SET @SQLString =  
    N'SELECT AVG(Loan_Amount) as Avg_Loan_Amount
 ,count(Loan_Amount)
 ,SUM(Loan_Amount) as Sum_Loan_Amount
 ,SQRT(SUM(Loan_Amount)) as Square_Loan_Amount
 ,Age_Band
 ,SUM(Interest_Paid_Amount) as Sum_Interest_Paid_Amount
 ,GETDATE()as today 
   FROM [dbo].[Loan]   
   group by @groupcol';  
SET @ParmDefinition = N'@groupcol nvarchar(50)'; 
SET @group=N'Age_Band'
exec  sp_executesql  @SQLString, @ParmDefinition,  
                  @groupcol = @group;

Answer 1

您不能在group by子句中使用参数，您可以使用参数构建查询字符串。这样的事情。

DECLARE @group nvarchar(50) = N'Age_Band'; --set col name
DECLARE @SQLString nvarchar(500);  
SET @SQLString =  
    N'SELECT AVG(Loan_Amount) as Avg_Loan_Amount
 ,count(Loan_Amount)
 ,SUM(Loan_Amount) as Sum_Loan_Amount
 ,SQRT(SUM(Loan_Amount)) as Square_Loan_Amount
 ,' + @group + ' 
 ,SUM(Interest_Paid_Amount) as Sum_Interest_Paid_Amount
 ,GETDATE()as today 
   FROM [dbo].[Loan]   
   group by ' + @group;  
exec  sp_executesql  @SQLString;

按照法规使用参数

1 个答案: