《2.5登錄用戶驗證功能設(shè)計》
效果圖:
畫面主要功能:新建數(shù)據(jù)庫疚宇、自行查詢數(shù)據(jù)庫并從程序中獲取數(shù)據(jù)庫中用戶表的完整數(shù)據(jù)。
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后臺數(shù)據(jù)庫表結(jié)構(gòu):
AOD.NET查詢數(shù)據(jù)庫的流程
1) 導(dǎo)入命名空間;
2) 定義數(shù)據(jù)庫連接字符串赏殃,創(chuàng)建Connection對象敷待;
3) 打開連接;
4) 利用Command對象的ExecuteReader()方法執(zhí)行Select查詢語句仁热;
5) 利用ExecuteReader()方法返回的DataReader對象讀取數(shù)據(jù)榜揖,顯示到界面上;
6) 關(guān)閉連接抗蠢。
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要代碼片段以及詳細(xì)描述
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 AdoNetDemo
{
public partial class DataBaseForm : Form
{
public DataBaseForm()
{
InitializeComponent();
}
private void DataBaseForm_Load(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();
// 在數(shù)據(jù)庫中查詢USERS表
String sqlStr = "select * from USERS";
SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);
SqlDataReader dr = cmd.ExecuteReader();
// 解析數(shù)據(jù)
while (dr.Read())
{
String Id = dr["ID"].ToString();
String Name = dr["NAME"].ToString();
String Password = dr["PASSWORD"].ToString();
String Phone = dr["PHONE"].ToString();
// 注意是累加
this.tb_Users.Text += Id + ", " + Name + ", " + Password + ", " + Phone + "\r\n";
}
}
catch (Exception exp)
{
MessageBox.Show("數(shù)據(jù)庫連接失敗" + exp.Message);
}
finally
{
sqlConn.Close();
}
}
private void tb_Users_TextChanged(object sender, EventArgs e)
{
}
}
}
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