学习在asp.net中使用存储过程

存储过程的定义：
CREATE procedure pro_buyGoods
(
@GoodsName varchar(30),
@GoodsNum int
)
AS
declare @count as int
set @count = (select count(*) from T_Goods where GoodsName=@GoodsName)
if @count<=0 begin
insert into T_Goods values (@GoodsName,@GoodsNum)
end
else begin
update T_Goods set GoodsNum=GoodsNum+@GoodsNum where GoodsName=@GoodsName
end
GO
说明：语法是通过检查的，这个过程是用来判断T_Goods表中有没有指定的商品，有的话则增加他的数目，没有的话新添加记录。

这是在ASP.NET中的调用过程：
int BuyGoodsID = Convert.ToInt32(this.txtBuyID.Text);
string GoodsName = this.txtGoodsName.Text;
int GoodsNum = Convert.ToInt32(this.txtGoodsNum.Text);
int GoodsPrice = Convert.ToInt32(this.txtGoodsPrice.Text);

SqlConnection conn = DB.CreateCon();
conn.Open();

string cmdText = "insert into T_BuyGoods values('"+BuyGoodsID+"','"+GoodsName+"','"+GoodsNum+"','"+GoodsPrice+"')";
SqlCommand cmd = new SqlCommand(cmdText,conn);

SqlTransaction trans = conn.BeginTransaction();
cmd.Transaction = trans;

try
{

cmd.ExecuteNonQuery();
//插入库存表的代码

SqlCommand cmd1 = new SqlCommand("pro_buyGoods",conn);
cmd1.CommandType = CommandType.StoredProcedure;
cmd1.Parameters.Add("@GoodsName",SqlDbType.VarChar);
cmd1.Parameters.Add("@GoodsNum",SqlDbType.Int);

cmd1.Parameters["@GoodsName"].Direction=ParameterDirection.Input;
cmd1.Parameters["@GoodsNum"].Direction=ParameterDirection.Input;
cmd1.Parameters["@GoodsName"].Value = GoodsName;
cmd1.Parameters["@GoodsNum"].Value = GoodsNum;

cmd1.ExecuteNonQuery();

this.Panel1.Visible = false;
this.Panel2.Visible = true;
this.lblInfo.Text = "提交成功！";
trans.Commit();
}
catch(Exception exp)
{
trans.Rollback();
Response.Write("<script language='javascript'>alert('提交失败，需要重新提交！')<"+"/script>");
}
finally
{
conn.Close();
}

***********************************************************************

set @count = (select count(*) from T_Goods where GoodsName=@GoodsName)
改为
select @count = count(*) from T_Goods where GoodsName=@GoodsName