C#调用存储过程出错,该如何处理

C#调用存储过程出错
CREATE   PROC   test(@Categories   varchar(500),@CategoriesType   int,
@CategoriesLastType   int,@CategoriesLastID   varchar(50),@CategoriesURL   varchar(500),
@GatherState   int,@GatherDate   DateTime,@CategoriesID   varchar(50),@CategoriesName   varchar(50),
@Type   int,@LastType   int)
AS
declare   @Count   int
declare   @SQL   varchar(1000)
begin
set   @SQL= 'select   ID   from   AmazonURL   where   Categories= '+@Categories+ '   and   CategoriesType= '+@Type+ '   and   CategoriesLastType= '+@LastType
@Count=exec(@SQL)
if(@Count> 0)
begin
set   @SQL= 'nsert   into   AmazonURL(Categories,CategoriesType,CategoriesLastType,CategoriesLastID,CategoriesURL,
GatherState,GatherDate,CategoriesID,CategoriesName)
values( '+@Categories+ ', '+@CategoriesType+ ', '+@CategoriesLastType+ ', '+@CategoriesLastID+ ', '+@CategoriesURL+ ',
'+@GatherState+ ', '+@GatherDate+ ', '+@CategoriesID+ ', '+@CategoriesName+ ') '
exec(@SQL)
end
end
go


在@Count=exec(@SQL)地方出错，我想返回查询后是否有值，如果没有值就是Count <0则添加数据，请大家帮忙

------解决方案--------------------
@Count=exec(@SQL)
这样不行嘀
用@str varchar(1000) output
------解决方案--------------------
jf up 学习
------解决方案--------------------
declare @SQL varchar(1000) output

@count= exec(@SQL)

------解决方案--------------------
exec @count=(@SQL)