第8章项目案例超市商品管理.docVIP

1、当表名与关键字冲突时需要使用中括号括引来 string sql string.Format Select count * from [User] where UserName 0 and PassWord 1 , txtUserName.Text.Trim , txtPwd.Text.Trim ; 2、新增商品信息事件 private void tsmiAdd_Click object sender, EventArgs e FrmEditComodity frmEditCommodity new FrmEditComodity ; frmEditCommodity.ShowDialog ; FillTable ; 3、是否是特价 private void chkIsDIscount_CheckedChanged object sender, EventArgs e if chkIsDIscount.Checked numReducedPrice.Enabled true; else numReducedPrice.Enabled false; numReducedPrice.Value numPrice.Value; 4、显示商品信息 private void ShowCommodity DBHelper dbh new DBHelper ; string sql string.Format select CommodityName,SortName,CommodityPrice,IsDiscount,reducedPrice from Commodity as C inner join CommoditySort as S on C.SortId S.SortId where commodityId 0 ,this.CommodityId ; dbh.OpenConnection ; SqlCommand comm new SqlCommand sql,dbh.Conn ; SqlDataReader reader comm.ExecuteReader ; while reader.Read this.txtName.Text reader[CommodityName].ToString ; this.cboSort.DisplayMember reader[SortName].ToString ; this.numPrice.Value Convert.ToDecimal reader[CommodityPrice] ; this.chkIsDIscount.Checked Convert.ToBoolean reader[IsDiscount] ; this.numReducedPrice.Value Convert.ToDecimal reader[ReducedPrice] ; 5、新增商品信息方法 private void InsertCommodity DBHelper dbhelper new DBHelper ; StringBuilder sb new StringBuilder ; sb.AppendFormat insert into Commodity values 0 , 1 , 2 , 3 , 4 ,this.txtName.Text.Trim , Convert.ToInt32 cboSort.SelectedValue ,numPrice.Value,this.chkIsDIscount.Checked ? 1:0,numReducedPrice.Value ; SqlCommand comm new SqlCommand sb.ToString ,dbhelper.Conn ; dbhelper.OpenConnection ; int result comm.ExecuteNonQuery ; if result 1 MessageBox.Show 增加信息成功 ; this.Close ; else MessageBox.Show 增加信息失败 ;