1城丧、貼效果圖延曙，最好是GIF文件

登陸界面.gif

2、描述畫面主要功能亡哄，列出支持功能后臺的數(shù)據(jù)庫表結(jié)構(gòu)

功能為：實(shí)現(xiàn)登錄信息到數(shù)據(jù)庫服務(wù)器上驗(yàn)證并登陸
數(shù)據(jù)庫結(jié)構(gòu)：

收銀員.PNG

庫管員.PNG

UserInfo.userId = int.Parse(dr["ID"].ToString());
UserInfo.userName = dr["NAME"].ToString();
UserInfo.userPwd = dr["PASSWORD"].ToString();
UserInfo.userPhone = dr["PHONE"].ToString();
UserInfo.userType = this.cbb_UserType.Text;

3枝缔、ADO.NET查詢數(shù)據(jù)庫流程

1.獲取連接字符串
2.連接數(shù)據(jù)庫,然后構(gòu)造查詢語句并提交查詢
3.獲取數(shù)據(jù)庫返回的數(shù)據(jù)
4.數(shù)據(jù)庫查詢結(jié)果展示如下：

數(shù)據(jù)庫功能圖.gif

4、貼入重要代碼

連接數(shù)據(jù)庫代碼

// 點(diǎn)擊“登錄”按鈕則登錄系統(tǒng)
    private void bt_Login_Click(object sender, EventArgs e)
    {
        String connStr = "Data Source=.;Initial Catalog=SuperMarketSales;Integrated Security=True";
        SqlConnection sqlConn = new SqlConnection(connStr);
        try
        {
            // 連接數(shù)據(jù)庫
            sqlConn.Open();

            // 注意USER是SQL Server關(guān)鍵字蚊惯，表名不能命名為USER愿卸，而應(yīng)當(dāng)用USERS
            String sqlStr = "select * from EMPLOYEE where ID=@id and PASSWORD=@pwd";
            SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);

            // 注意是用用戶ID登錄，而不是用戶名拣挪，用戶名可能會重復(fù)
            cmd.Parameters.Add(new SqlParameter("@id",      this.tb_User.Text.Trim()));
            cmd.Parameters.Add(new SqlParameter("@pwd", this.tb_Password.Text.Trim()));

            SqlDataReader dr = cmd.ExecuteReader();

            // 如果從數(shù)據(jù)庫中查詢到記錄擦酌，則表示可以登錄
            if (dr.HasRows)
            {
                dr.Read();
                UserInfo.userId = int.Parse(dr["ID"].ToString());
                UserInfo.userName = dr["NAME"].ToString();
                UserInfo.userPwd = dr["PASSWORD"].ToString();
                UserInfo.userType = dr["TYPE"].ToString();
                UserInfo.userPhone = dr["PHONE"].ToString();

                MessageBox.Show(UserInfo.userType + "登錄成功");

                if (UserInfo.userType == "收銀員")
                {
                    // 顯示收銀員主界面
                    MainFormUser formUser = new MainFormUser();
                    formUser.Show();

                    // 隱藏登錄界面
                    this.Hide();
                }

                if (UserInfo.userType == "庫管員")
                {
                    // 顯示庫管員主界面
                    MainFormAdmin formAdmin = new MainFormAdmin();
                    formAdmin.Show();

                    // 隱藏登錄界面
                    this.Hide();
                }
            }
            else
            {
                MessageBox.Show("用戶名或密碼錯誤", "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        catch (Exception exp)
        {
            MessageBox.Show("數(shù)據(jù)庫連接失敗");
            return;
        }
        finally
        {
            sqlConn.Close();
        }
    }

數(shù)據(jù)庫中查詢語句

String sqlStr = "select * from USERS";
 SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);
 SqlDataReader dr = cmd.ExecuteReader();

分析數(shù)據(jù)語句

while (dr.Read())
 {
 String Id = dr["ID"].ToString();
 String Name = dr["NAME"].ToString();
 String Password = dr["PASSWORD"].ToString();
 String Phone = dr["PHONE"].ToString();