该系统工作流程:超市工作人员在管理商品时，用户对商品的价格，折扣等进行管理，并进行增删改。(1)该管理软件将对商品进行管理和统计,对产品的价格进行录入管理和统计;(2)根据需要对商品名称、价格、是否打折等进行查询，并能显示详细信息；(3)为用户提供账号管理工具，以便用户对账号进行管理，具体为登录修改用户密码；(4)提供商品的增加，删除，修改，对商品进行管理，还可以分类查看打折商品和原价商品。数据库中需要存储的数据:用户登录名、密码、商品名称、价格、是否打折、商品类别、打折价格等。

private void frmEditCommodity_Load(object sender, EventArgs e)        {            if (commodityID==0)//添加            {                this.GetCommoditySort();            }            else//修改            {                this.GetCommodity();                this.btnSave.Text = "修改";            }        } private void btnSave_Click(object sender, EventArgs e)//保存        {            if (CheckInput())            {                if (commodityID==0)//新增                {                    InsertCommodity();                }                else//修改                {                    UpdateCommodity();                }            }        }private void chkIsPrice_CheckStateChanged(object sender, EventArgs e) //选择被更改        {            if ( chkIsPrice .Checked)            {                this.numReducedPrice.Enabled = true;            }            else            {                this.numReducedPrice.Enabled = false;                this.numReducedPrice.Value = this.numPrice.Value;            }        } 新增商品的方法：private void InsertCommodity()        {            DBHelper db = new DBHelper();            try            {                //sql语句                string sql = string.Format("insert into Commodity(CommodityName,SortID,CommodityPrice,IsDiscount,ReducedPrice) values('{0}','{1}','{2}','{3}','{4}')",                    txtName.Text.Trim(), Convert.ToInt32(cboSort.SelectedValue), this.numPrice.Value,                    this.chkIsPrice.Checked ? 1 : 0, numReducedPrice.Value);                Console.WriteLine(sql);                SqlCommand cmd = new SqlCommand(sql, db.Connection);//执行工具                db.OpenConnection();//打开数据库连接                int result = cmd.ExecuteNonQuery(); //执行                if (result==1)                {                    MessageBox.Show ("添加成功","系统提示",MessageBoxButtons.OK,MessageBoxIcon.Information );                    this.Close();            }            }            catch (Exception )            {                MessageBox.Show("数据库操作失败, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);            }            finally            {             }        }修改商品的方法：private void UpdateCommodity()        {            DBHelper helper = new DBHelper();            try            {                string sql = string.Format("update Commodity set Commodity.CommodityName ='{0}',Commodity.SortID='{1}',Commodity.CommodityPrice ='{2}', Commodity.IsDiscount ='{3}',Commodity.ReducedPrice ='{4}' where Commodity.CommodityID ='{5}'",txtName.Text.Trim(),Convert.ToInt32 (cboSort .SelectedValue),this.numPrice.Value ,this.chkIsPrice.Checked?1:0,numReducedPrice .Value ,this.commodityID);                //执行工具                SqlCommand cmd = new SqlCommand(sql.ToString(), helper.Connection);                  helper.OpenConnection();//打开数据库连接                int result = cmd.ExecuteNonQuery()//执行                if (result == 1)//判断                {                    MessageBox.Show("修改成功", "系统提示?", MessageBoxButtons.OK, MessageBoxIcon.Information);                    this.Close();                }            }            catch (Exception )            {                MessageBox.Show("数据库操作发生错误", "系统提示",MessageBoxButtons.OK, MessageBoxIcon.Information);            }            finally            {                helper.CloseConnection();            }        }删除商品方法：private void DeleteCommodityByID()        {            if (this.dgvCommodity.CurrentRow != null)            {                DialogResult dr = MessageBox.Show("确定要删除名称为" dgvCommodity.CurrentRow.Cells[1].Value, "系统提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);                if (dr == DialogResult.OK)                {                    DBHelper helper = new DBHelper();                    try                    {                        //sql语句                        StringBuilder sb = new StringBuilder();                        sb.AppendFormat("delete from Commodity where CommodityID={0}", Convert.ToInt32(dgvCommodity.CurrentRow.Cells[0].Value));                        //执行                        SqlCommand cmd = new SqlCommand(sb.ToString(), helper.Connection);                        //打开数据库连接                        helper.OpenConnection();                        //执行                        int result = cmd.ExecuteNonQuery();                        if (result == 1)                        {                            MessageBox.Show("删除成功!", "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                            //重新绑定dgv                            this.FillCommodityInfo();                        }                    }                    catch (Exception)                    {                        MessageBox.Show("数据库操作失败, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                    }                    finally                    {                        helper.CloseConnection();                    }                }            }        }