int a = 1;
        Params1[0] = DB.MakeInParam("@CourseID", SqlDbType.Int, 4, a);               //试卷编号      
        DataSet ds1 = DB.GetDataSet("Proc_PaperDetail",Params1);
        GridView2.DataSource = ds1;
        GridView2.DataBind();

        SqlParameter[] Params2 = new SqlParameter[1];
        int b = 2;
        Params2[0] = DB.MakeInParam("@CourseID", SqlDbType.Int, 4, b);               //试卷编号      
        DataSet ds2 = DB.GetDataSet("Proc_PaperDetail", Params2);
        GridView5.DataSource = ds2;

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO



ALTER PROCEDURE [dbo].[Proc_PaperDetail]
        (@CourseID        [int])
AS
begin 
    declare @sql nvarchar(1000)
if @CourseID=1
 begin    
    set @sql='select * from MultiProblem where CourseID=@CourseID'
    exec sp_executesql @sql        
 end
else if @CourseID=2
 begin    
    set @sql='select * from MultiProblem where CourseID=@CourseID'
    exec sp_executesql @sql        
 end
else if @CourseID=3
 begin    
    set @sql='select * from MultiProblem where CourseID=@CourseID'
    exec sp_executesql @sql        
 end
else if @CourseID=4
 begin    
    set @sql='select * from MultiProblem where CourseID=@CourseID'
    exec sp_executesql @sql        
 end
else
 begin    
    set @sql='select * from MultiProblem where CourseID=@CourseID'
    exec sp_executesql @sql        
 end
end

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO



ALTER PROCEDURE [dbo].[Proc_PaperDetail]
        (@CourseID        [int])
AS
begin 
    declare @sql nvarchar(1000)
if @CourseID=1
 begin    
    set @sql='select * from MultiProblem where CourseID='+rtrim(@CourseID)
    exec sp_executesql @sql        
 end
else if @CourseID=2
 begin    
    set @sql='select * from MultiProblem where CourseID='+rtrim(@CourseID)
    exec sp_executesql @sql        
 end
else if @CourseID=3
 begin    
    set @sql='select * from MultiProblem where CourseID='+rtrim(@CourseID)
    exec sp_executesql @sql        
 end
else if @CourseID=4
 begin    
    set @sql='select * from MultiProblem where CourseID='+rtrim(@CourseID)
    exec sp_executesql @sql        
 end
else
 begin    
    set @sql='select * from MultiProblem where CourseID='+rtrim(@CourseID)
    exec sp_executesql @sql        
 end
end

------解决方案--------------------
表名或者字段名位变量的时候 需要用动态SQL。

------解决方案--------------------
SQL code

alter procedure [dbo].[proc_paperdetail] ( @courseid int )
as 
    begin 
        declare @sql nvarchar(4000)
        set @sql = 'select * from multiproblem where courseid='
            + ltrim(@courseid)   
        exec (@sql)        
    end