测试1.书店的增删改查项目.链接数据库

0.1创建数据库

0.2向数据库内添加数据

0.3创建一个辅助类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Library
{
    public class SqlTools
    {
        public static string str = "Data Source=.;Initial Catalog=Library;Uid=sa";
    }
}

0.4创建主窗体如图

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace Library
{
    public partial class Homepage : Form
    {
        public Homepage()
        {
            InitializeComponent();
        }
        DataSet ds = new DataSet();//连接数据集
        private void Homepage_Load(object sender, EventArgs e)
        {
           //主窗体
            Show();//调用所有书的方法
        }
        #region 显示所有的书的方法
        public void Show()
        {
            SqlConnection con = new SqlConnection(SqlTools.str);//创建 Connection对象
            //SQL语句
            string sql = "select * from Homepage";
            //创建DataAdapter数据适配器
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            //填充数据
            da.Fill(ds, "Homepage");
            //数据源
            dvgList.DataSource = ds.Tables["Homepage"];

        } 
        #endregion

        #region 查询判断的方法
        public void Type()
        {
            DataView dv = new DataView(ds.Tables["Homepage"]);
            if (!(txtBookName.Text.Trim().Equals("")) && (txtAuthor.Text.Trim().Equals("")))
            {
                dv.RowFilter = "BookName like'%" + txtBookName.Text + "%'";
                dvgList.DataSource = dv;
            }
            else if ((txtBookName.Text.Trim().Equals("")) && (!txtAuthor.Text.Trim().Equals("")))
            {
                dv.RowFilter = "Author like'%" + txtAuthor.Text + "%'";
                dvgList.DataSource = dv;
            }
            else
            {
                MessageBox.Show("没有您查询的书!");
            }

        } 
        #endregion

        private void btnInquiry_Click(object sender, EventArgs e)
        {
            Type();//调用查询的方法
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            //新增
            FrmMain  frm = new FrmMain ();
            frm.stu = this;
            frm.Show();
        }

        private void 删除ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //删除
            #region 删除
            if (dvgList.SelectedRows[0] != null)
            {
                string name = dvgList.SelectedRows[0].Cells["BookName"].Value.ToString();
                SqlConnection con = new SqlConnection(SqlTools.str);
                string sql = "Delete from Homepage where BookName='" + name + "'";
                SqlCommand cmd = new SqlCommand(sql, con);
                try
                {
                    con.Open();
                    int result = Convert.ToInt32(cmd.ExecuteScalar());
                    if (result > 0)
                    {
                        MessageBox.Show("删除成功!");
                    }
                    else
                    {
                        MessageBox.Show("删除失败!");
                    }

                }
                catch (Exception)
                {
                    MessageBox.Show("网络连接异常!");
                    throw;
                }
                finally
                {
                    con.Close();
                }
            } 
            #endregion
        }
        #region 刷新
        public void input()
        {
            if (ds.Tables[0] != null)
            {
                ds.Tables["Homepage"].Clear();
            }
            Show();
        } 
        #endregion
        
        private void 修改ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FrmMain frm = new FrmMain();
            frm.Text = "修改";
            if (dvgList .SelectedRows [0]!=null )
            {
                string name = dvgList.SelectedRows[0].Cells["BookName"].Value.ToString();
                frm.BookName = name;
            }
            frm.stu = this;
            frm.Show();
        }



        

    }
}

0.5创建新增页面

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace Library
{
    public partial class FrmMain : Form
    {
        public FrmMain()
        {
            InitializeComponent();
            
        }
        public Homepage stu;
        public string BookName;
        
        private void btnCancel_Click(object sender, EventArgs e)
        {


        }
        SqlConnection con = new SqlConnection(SqlTools .str ); 
        private void btnConservation_Click(object sender, EventArgs e)
        {
            //保存
            if (this.Text .Trim ().Equals ("新增"))
            {
                insert();  
            }
            else if (this.Text .Trim ().Equals ("修改"))
            {
                update();
            }
        }
        public void insert()
        {
            con.Open();
            string sql = "insert into Homepage values('" + txtBookName.Text + "','" + txtAuthor.Text + "','" + txtPrice.Text + "','" + txtQuantity .Text+ "')";
            SqlCommand cmd = new SqlCommand(sql, con);
            try
            {
                int retult = Convert.ToInt32(cmd.ExecuteScalar());
                if (retult >= 0)
                {
                    MessageBox.Show("增加成功!");
                }
                else
                {
                    MessageBox.Show("增加失败!");
                }
            }
            catch (Exception)
            {
                MessageBox.Show("连接发生异常!");
                throw;
            }
            finally
            {
                con.Close();
            }
            stu.input();
        }
        public void update()
        {
            con.Open();
            string sql = "update Homepage set BookName='"+txtBookName.Text +"','"+txtAuthor.Text+"','"+txtPrice.Text+"','"+txtQuantity.Text+"'where BookName='"+BookName +"'";
            SqlCommand cmd = new SqlCommand(sql,con );
            try
            {
                int retult = Convert.ToInt32(cmd.ExecuteScalar());
                if (retult >= 0)
                {
                    MessageBox.Show("修改成功!");
                }
                else
                {
                    MessageBox.Show("修改失败!");
                }

            }
            catch (Exception)
            {
                MessageBox.Show("连接异常!");
                throw;
            }
            finally
            {
                con.Close();
            }
            stu.input();
        }

        private void FrmMain_Load(object sender, EventArgs e)
        {
            //主窗体
            txtBookName.Text = BookName;
        }
       
    }
}

0.6实现页面效果展示