My Procedure not have output in C# for Datasoure GridView

Question

hi all,

I have a procedure:

ALTER Procedure [dbo].[Prc_TBMonPerfSecNBase_BlnForm](@P_Year varchar(4),@P_Month varchar(2))
As
Declare    @Cols    varchar(max),
           @Sql     varchar(max)

Select     @Cols=Stuff((Select ',''''AS ' + quotename(Sec_Name)+',''''AS '+quotename(Sec_Code)
                              From Tb_Section
                             Where    Sec_Base    = 1
                            For xml path('')), 1, 1, '')
Set    @Sql    = 'Select Sec_Name,
                            Sec_Code,'
                            +@P_Year+'[???]'+
                            ','
                            +@P_Month+'[???]'+
                            ','
                            + @Cols
                 + 'From   Tb_Section Where Sec_Base = 0 Order by Sec_Name'

exec    (@Sql)

 this procedure has output in Sql.But When this procedure set Datagridview.DataSource,DataGridView not have any row.

why?

please help me...

thanks