.NET数据库编程求索之路3.使用ADO.NET实现（SQL语句篇）（2）

3.使用ADO.NET实现（SQL语句篇）（2）

3.3  FormEdit新增/修改窗体代码

代码3-3 FormEdit 窗体代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;//新添命名空间
using System.Configuration;//新添命名空间

namespace HomeShop.WinForm
{
    //功能：订单管理系统-新增/修改订单窗体；
    //作者：夏春涛；
    //日期：2011-11-30；
    public partial class FormEdit : Form
    {
        //数据库连接字符串
        private string connectionString = ConfigurationManager.ConnectionStrings["HomeShop"].ConnectionString;
        
        //当前操作状态，默认为"ADD"
        private string operationState = "ADD";//ADD：新增；UPDATE：修改；

        //当前订单的ID，默认为0
        private int currentOrderID = 0;

        //当前订单关联的订购商品信息数据
        private DataTable orderItems = new DataTable();

        //临时ID，起始值为0，自动递减（避免与正常的正整数ID重复）
        private int tempID = 0;

        //【窗体构造函数】
        public FormEdit()
        {
            InitializeComponent();            
        }

        //【窗体构造函数】-重载，入参：要修改的订单的ID
        public FormEdit(int orderID)
        {
            InitializeComponent();
            this.currentOrderID = orderID;
            this.operationState = "UPDATE";
        }

        //【窗体加载事件】-初始化控件的内容
        private void FormEdit_Load(object sender, EventArgs e)
        {
            this.Text = "新增订单";//窗体标题
            gridView.AutoGenerateColumns = false;//禁止DataGridView控件自动生成列
            OrderID.Text = this.currentOrderID.ToString();            
            InitOrderState();//初始化订单状态下拉框
            InitOrderItems();//初始化订购商品列表 
            
            if ("UPDATE" == this.operationState)//在订单修改状态下
            {
                this.Text = "修改订单";//窗体标题
                InitOrderBaseInfo();//初始化订单基本信息
                GetOrderTotal();//获取订单总金额
            }            
        }

        //初始化订单状态下拉框
        private void InitOrderState()
        {
            //从数据库获取订单状态数据
            SqlConnection connection = new SqlConnection(connectionString);
            connection.Open();
            string sql = @"SELECT * FROM [OrderState]
                           ORDER BY [Code]";
            SqlCommand command = new SqlCommand(sql, connection);
            SqlDataAdapter adapter = new SqlDataAdapter(command);
            DataTable dataTable = new DataTable();
            adapter.Fill(dataTable);
            connection.Close();
            //将数据绑定到订单状态下拉框
            OrderState.ValueMember = "Code";
            OrderState.DisplayMember = "Name";
            OrderState.DataSource = dataTable;
        }

        //初始化订单基本信息
        private void InitOrderBaseInfo()
        {
            //从数据库中获取当前订单基本信息
            SqlConnection connection = new SqlConnection(connectionString);
            connection.Open();            
            string sql = @"SELECT * FROM [Order]
                           WHERE [OrderID] = @OrderID";
            SqlCommand command = new SqlCommand(sql, connection);
            command.Parameters.Add(new SqlParameter("@OrderID", currentOrderID));
            SqlDataAdapter adapter = new SqlDataAdapter(command);
            DataTable dataTable = new DataTable();
            adapter.Fill(dataTable);
            connection.Close(); 
            //将当前订单基本信息显示在编辑区
            OrderID.Text = dataTable.Rows[0]["OrderID"].ToString();
            CustomerName.Text = dataTable.Rows[0]["CustomerName"].ToString();
            CustomerPhoneNo.Text = dataTable.Rows[0]["CustomerPhoneNo"].ToString();
            CustomerAddress.Text = dataTable.Rows[0]["CustomerAddress"].ToString();
            OrderTime.Value = Convert.ToDateTime(dataTable.Rows[0]["OrderTime"]);
            OrderState.SelectedValue = dataTable.Rows[0]["OrderStateCode"].ToString();
        }

        //初始化当前订单关联的商品列表
        private void InitOrderItems()
        {
            SqlConnection connection = new SqlConnection(connectionString);
            connection.Open();
            string sql = @"SELECT [OrderItemID],
                                  [Product],
                                  [UnitPrice],
                                  [Quantity],
                                  [UnitPrice]*[Quantity] AS SubTotal
                           FROM [OrderItem]
                           WHERE [OrderID] = @OrderID
                           ORDER BY [OrderItemID]";
            SqlCommand command = new SqlCommand(sql, connection);
            command.Parameters.Add(new SqlParameter("@OrderID", currentOrderID));
            SqlDataAdapter adapter = new SqlDataAdapter(command);            
            adapter.Fill(this.orderItems);
            connection.Close();

            this.orderItems.PrimaryKey = new DataColumn[] { this.orderItems.Columns["OrderItemID"] };
            gridView.DataSource = this.orderItems;
        }

        //计算当前订单的总金额
        private void GetOrderTotal()
        {
            decimal orderTotal = 0m;
            //通过累加数据列表中的“小计”来计算当前订单的总金额
            for (int i = 0; i < gridView.RowCount; i++)
            {
                orderTotal += (decimal)gridView.Rows[i].Cells["Col_SubTotal"].Value;
            }
            OrderTotal.Text = orderTotal.ToString();
        }        

        //【新增】商品
        private void btnProductAdd_Click(object sender, EventArgs e)
        {
            if (!ValidateInput_Product()) return;//验证用户输入

            string product = Product.Text.Trim();
            decimal unitPrice = Convert.ToDecimal(UnitPrice.Text.Replace(" ",""));
            int quantity = Convert.ToInt32(Quantity.Text.Replace(" ",""));
            decimal subtotal = (decimal)unitPrice * quantity;

            DataRow row = this.orderItems.NewRow();
            row["OrderItemID"] = tempID--;
            row["Product"] = product;
            row["UnitPrice"] = unitPrice;
            row["Quantity"] = quantity;
            row["Subtotal"] = subtotal;
            this.orderItems.Rows.Add(row);
         
            gridView.DataSource = this.orderItems;            
            GetOrderTotal();
            gridView.Rows[gridView.Rows.Count - 1].Selected = true;
        }

        //验证用户输入-新增/修改商品信息时
        private bool ValidateInput_Product()
        {
            //验证商品名称
            if ("" == Product.Text.Trim())
            {
                MessageBox.Show(this, "请输入商品名称！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                Product.Focus();
                return false;
            }
            //验证商品单价            
            try
            {
                string regexString = @"^[0-9]*[0-9]+[\.]*[0-9]*$";//正则表达式-非负数
                RegexStringValidator validator = new RegexStringValidator(regexString);
                validator.Validate(UnitPrice.Text.Replace(" ", ""));
            }
            catch
            {
                MessageBox.Show(this, "请输入正确的商品单价（非负数）！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                UnitPrice.Focus();
                return false;
            }
            //验证商品数量            
            try
            {
                string regexString = @"^[0-9]*[1-9][0-9]*$";//正则表达式-正整数
                RegexStringValidator validator = new RegexStringValidator(regexString);
                validator.Validate(Quantity.Text.Replace(" ", ""));
            }
            catch
            {
                MessageBox.Show(this, "请输入正确的商品数量（正整数）！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                Quantity.Focus();
                return false;
            }

            return true;
        }

        //【修改】选中的商品
        private void btnProductUpdate_Click(object sender, EventArgs e)
        {
            if (gridView.RowCount == 0) return;
            if (!ValidateInput_Product()) return;

            int selectedRowIndex = gridView.SelectedRows[0].Index;

            int orderItemID = (int)gridView.Rows[selectedRowIndex].Cells["Col_OrderItemID"].Value;
            string product = Product.Text.Trim();
            decimal unitPrice = Convert.ToDecimal(UnitPrice.Text.Replace(" ", ""));
            int quantity = Convert.ToInt32(Quantity.Text.Replace(" ", ""));
            decimal subtotal = (decimal)unitPrice * quantity;

            DataRow row = this.orderItems.Rows.Find(orderItemID);
            row["Product"] = product;
            row["UnitPrice"] = unitPrice;
            row["Quantity"] = quantity;
            row["Subtotal"] = subtotal;

            gridView.DataSource = this.orderItems;            
            GetOrderTotal();
            gridView.Rows[selectedRowIndex].Selected = true;
        }

        //【删除】选中的商品
        private void btnProductDelete_Click(object sender, EventArgs e)
        {
            if (gridView.RowCount == 0) return;            
            
            DialogResult dlgResult = MessageBox.Show(this, "确认要删除选中的商品吗？", "提示", 
                                                MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (DialogResult.Yes == dlgResult)
            {
                int selectedRowIndex = gridView.SelectedRows[0].Index; 
                
                int orderItemID = (int)gridView.SelectedRows[0].Cells["Col_OrderItemID"].Value;
                this.orderItems.Rows.Find(orderItemID).Delete(); 
               
                gridView.DataSource = this.orderItems;                 
                GetOrderTotal();
                //选中下一条记录
                if (selectedRowIndex > gridView.Rows.Count - 1)
                    selectedRowIndex = gridView.Rows.Count - 1;
                if (selectedRowIndex >= 0)
                {
                    gridView.Rows[selectedRowIndex].Selected = true;
                    ShowSelectedRowInfo();//将选中的商品信息显示在编辑区
                }
            }
        }

        //【选择更改事件】-将选中的商品信息显示在编辑区
        private void gridView_SelectionChanged(object sender, EventArgs e)
        {
            ShowSelectedRowInfo();
        }

        //将选中的商品信息显示在编辑区
        private void ShowSelectedRowInfo()
        {
            if (gridView.SelectedRows.Count == 0) return;
            Product.Text = gridView.SelectedRows[0].Cells["Col_Product"].Value.ToString();
            UnitPrice.Text = gridView.SelectedRows[0].Cells["Col_UnitPrice"].Value.ToString();
            Quantity.Text = gridView.SelectedRows[0].Cells["Col_Quantity"].Value.ToString();
        }        

        //【确定】-保存新增/修改的订单
        private void btnOK_Click(object sender, EventArgs e)
        {
            if (!ValidateInput_Order()) return;//验证用户输入

            if ("ADD"==this.operationState)//新增订单
            {
                AddOrder();
                MessageBox.Show(this, "新增订单成功！", "提示", 
                    MessageBoxButtons.OK, MessageBoxIcon.Information);                
            }
            if ("UPDATE" == this.operationState)//修改订单
            {
                UpdateOrder();
                MessageBox.Show(this, "修改订单成功！", "提示",
                    MessageBoxButtons.OK, MessageBoxIcon.Information);     
            }            
            
            this.DialogResult = DialogResult.OK;//设置对话框结果
            this.Close();//关闭窗体
        }

        //验证用户输入-保存新增/修改的订单时
        private bool ValidateInput_Order()
        {
            //验证顾客姓名
            if ("" == CustomerName.Text.Trim())
            {
                MessageBox.Show(this, "请输入顾客姓名！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                CustomerName.Focus();
                return false;
            }
            //验证联系电话
            if ("" == CustomerPhoneNo.Text.Trim())
            {
                MessageBox.Show(this, "请输入联系电话！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                CustomerPhoneNo.Focus();
                return false;
            }
            //订购商品信息
            if (0 == gridView.Rows.Count)
            {
                MessageBox.Show(this, "请输入订购商品信息！", "提示",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                Product.Focus();
                return false;
            }

            return true;
        }

        //添加订单到数据库
        private int AddOrder()
        {
            int rowsCountAffected = 0;
            SqlConnection connection = new SqlConnection(connectionString);
            connection.Open();
            //开始数据库事务
            SqlTransaction trans = connection.BeginTransaction();
            SqlCommand command = new SqlCommand();
            command.Connection = connection;
            command.Transaction = trans;
            try
            {
                //新增订单基本信息，并使用SQL的系统函数@@IDENTITY获取新增订单的ID
                string sql = @"INSERT INTO [Order]([OrderTime],
                                                   [OrderStateCode],
                                                   [CustomerName],
                                                   [CustomerPhoneNo],
                                                   [CustomerAddress])
                               VALUES(@OrderTime,
                                      @OrderStateCode,
                                      @CustomerName,
                                      @CustomerPhoneNo,
                                      @CustomerAddress)
                               SET @OrderID = @@IDENTITY ";
                command.CommandText = sql;
                command.Parameters.Add(new SqlParameter("@OrderTime", OrderTime.Value));
                command.Parameters.Add(new SqlParameter("@OrderStateCode", OrderState.SelectedValue.ToString()));
                command.Parameters.Add(new SqlParameter("@CustomerName", CustomerName.Text.Trim()));
                command.Parameters.Add(new SqlParameter("@CustomerPhoneNo", CustomerPhoneNo.Text.Trim()));
                command.Parameters.Add(new SqlParameter("@CustomerAddress", CustomerAddress.Text.Trim()));
                //@OrderID作为传出参数，用于获取新增订单的ID
                SqlParameter paramOrderID = new SqlParameter("@OrderID", SqlDbType.Int);
                paramOrderID.Direction = ParameterDirection.Output;
                command.Parameters.Add(paramOrderID);
                rowsCountAffected = command.ExecuteNonQuery();
                this.currentOrderID = (int)paramOrderID.Value;
                command.Parameters.Clear();//清空参数列表，避免参数重名问题
                //-----------------------------------------------------------
                //循环添加订购商品信息
                for (int i = 0; i < this.orderItems.Rows.Count; i++)
                {
                    sql = @"INSERT INTO [OrderItem]([OrderID],
                                                [Product],
                                                [UnitPrice],
                                                [Quantity])
                            VALUES( @OrderID,
                                    @Product,
                                    @UnitPrice,
                                    @Quantity)";
                    command.CommandText = sql;

                    DataRow row = this.orderItems.Rows[i];
                    command.Parameters.Add(new SqlParameter("@OrderID", this.currentOrderID));
                    command.Parameters.Add(new SqlParameter("@Product", row["Product"].ToString()));
                    command.Parameters.Add(new SqlParameter("@UnitPrice", (decimal)row["UnitPrice"]));
                    command.Parameters.Add(new SqlParameter("@Quantity", (int)row["Quantity"]));
                    rowsCountAffected += command.ExecuteNonQuery();
                    command.Parameters.Clear();//清空参数列表，避免参数重名问题
                }
                trans.Commit();//提交数据库事务
            }
            catch
            {
                trans.Rollback();//回滚数据库事务
                throw;
            }
            connection.Close();

            return rowsCountAffected;
        }

        //修改订单到数据库
        private int UpdateOrder()
        {
            int rowsCountAffected = 0;
            SqlConnection connection = new SqlConnection(connectionString);
            connection.Open();
            //开始数据库事务
            SqlTransaction trans = connection.BeginTransaction();
            SqlCommand command = new SqlCommand();
            command.Connection = connection;
            command.Transaction = trans;
            try
            {
                //修改订单基本信息
                string sql = @"UPDATE [Order]
                               SET [OrderTime] = @OrderTime,
                                   [OrderStateCode] = @OrderStateCode,
                                   [CustomerName] = @CustomerName,
                                   [CustomerPhoneNo] = @CustomerPhoneNo,
                                   [CustomerAddress] = @CustomerAddress
                               WHERE [OrderID] = @OrderID";
                command.CommandText = sql;
                command.Parameters.Add(new SqlParameter("@OrderTime", OrderTime.Value));
                command.Parameters.Add(new SqlParameter("@OrderStateCode", OrderState.SelectedValue.ToString()));
                command.Parameters.Add(new SqlParameter("@CustomerName", CustomerName.Text.Trim()));
                command.Parameters.Add(new SqlParameter("@CustomerPhoneNo", CustomerPhoneNo.Text.Trim()));
                command.Parameters.Add(new SqlParameter("@CustomerAddress", CustomerAddress.Text.Trim()));
                command.Parameters.Add(new SqlParameter("@OrderID", currentOrderID));
                rowsCountAffected = command.ExecuteNonQuery();
                command.Parameters.Clear();//清空参数列表，避免参数重名问题
                //-----------------------------------------------------------
                //循环将订购商品信息列表同步更新到数据库中
                for (int i = 0; i < this.orderItems.Rows.Count; i++)
                {
                    DataRow row = this.orderItems.Rows[i];

                    if (DataRowState.Added == row.RowState)//新增
                    {
                        sql = @"INSERT INTO [OrderItem]([OrderID],
                                                [Product],
                                                [UnitPrice],
                                                [Quantity])
                                VALUES( @OrderID,
                                        @Product,
                                        @UnitPrice,
                                        @Quantity)";
                        command.CommandText = sql;
                        command.Parameters.Add(new SqlParameter("@OrderID", this.currentOrderID));
                        command.Parameters.Add(new SqlParameter("@Product", row["Product"].ToString()));
                        command.Parameters.Add(new SqlParameter("@UnitPrice", (decimal)row["UnitPrice"]));
                        command.Parameters.Add(new SqlParameter("@Quantity", (int)row["Quantity"]));
                        rowsCountAffected += command.ExecuteNonQuery();
                        command.Parameters.Clear();//清空参数列表，避免参数重名问题
                    }
                    if (DataRowState.Modified == row.RowState)//修改
                    {
                        sql = @"UPDATE [OrderItem]
                                SET [OrderID] = @OrderID,
                                    [Product] = @Product,
                                    [UnitPrice] = @UnitPrice,
                                    [Quantity] = @Quantity
                                WHERE [OrderItemID] = @OrderItemID";
                        command.CommandText = sql;
                        command.Parameters.Add(new SqlParameter("@OrderID", this.currentOrderID));
                        command.Parameters.Add(new SqlParameter("@Product", row["Product"].ToString()));
                        command.Parameters.Add(new SqlParameter("@UnitPrice", (decimal)row["UnitPrice"]));
                        command.Parameters.Add(new SqlParameter("@Quantity", (int)row["Quantity"]));
                        command.Parameters.Add(new SqlParameter("@OrderItemID", (int)row["OrderItemID"]));
                        rowsCountAffected += command.ExecuteNonQuery();
                        command.Parameters.Clear();//清空参数列表，避免参数重名问题
                    }
                    if (DataRowState.Deleted == row.RowState)//删除
                    {
                        sql = @"DELETE FROM [OrderItem]
                                WHERE [OrderItemID] = @OrderItemID";
                        command.CommandText = sql;
                        command.Parameters.Add(new SqlParameter("@OrderItemID", (int)row["OrderItemID",DataRowVersion.Original]));
                        rowsCountAffected += command.ExecuteNonQuery();
                        command.Parameters.Clear();//清空参数列表，避免参数重名问题
                    }
                }

                trans.Commit();//提交数据库事务
            }
            catch
            {
                trans.Rollback();//回滚数据库事务
                throw;
            }
            connection.Close();

            return rowsCountAffected;
        }

        //【取消】-关闭窗体
        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.Close();//关闭窗体
        }
    }
}

数据库文件：/Files/SummerRain/NetDbDevRoad/HomeShopDB.rar

完整源代码：/Files/SummerRain/NetDbDevRoad/3使用ADONET实现SQL语句篇.rar

 转载请注明：【 夏春涛 email: xchuntao@163.com  blog: http://www.cnblogs.com/SummerRain 】