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

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(
@"Data Source=.\SQLEXPRESS;AttachDBFilename=|DataDirectory|\mydb.mdf;Integrated Security=True;User Instance=True"))
            {
                con.Open();
                using (SqlCommand cmd = con.CreateCommand())
                {
                     = "Select * from Table1 where username=@un";
                    cmd.Parameters.Add(new SqlParameter("un", textBox1.Text));
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            string pw = reader.GetString(reader.GetOrdinal("password"));
                            if (pw == textBox2.Text)
                            {
                                MessageBox.Show("登陆成功！");
                            }
                            else
                            {
                                MessageBox.Show("登录失败！");
                            }
                        }
                        else
                        {
                            MessageBox.Show("用户名不存在！");
                        }
                    }
                }
            }




        }

        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(
@"Data Source=.\SQLEXPRESS;AttachDBFilename=|DataDirectory|\mydb.mdf;Integrated Security=True;User Instance=True"))
            {
                con.Open();
      
                  
                   string upd = "Insert into Table1(username,password) values('textBox1.Text' ,'textBox2.Text')";
                 
                   SqlCommand mycmd = new SqlCommand(upd,con);
                    MessageBox.Show("注册成功！！");
               
            }
        }
    }
}


说明：快速注册的功能是向数据库插入数据，但是调试之后去数据库查看，并没有插入新数据。编译没有出错~

你的mycmd没执行ExecuteNonQuery()方法，再一个是你的SQL语句有问题,应该是Values ('"+Text1.Text+"','"+Text2.Text+"'")

[ 本帖最后由 winners 于 2012-1-27 20:13 编辑 ]

同意楼上

string upd = "Insert into Table1(username,password) values('" + textBox1.Text + "' ,'" + textBox2.Text + "')";
mycmd.ExecuteNonQuery();
使用存储过程吧，不要再程序中直接使用SQL语句

别的问题也很多唉 都是新人常犯的毛病 还得多练习啊
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    { //命名不规范
        public Form1()
        {
            InitializeComponent();
        }
  //注释呢？
        private void button1_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(
@"Data Source=.\SQLEXPRESS;AttachDBFilename=|DataDirectory|\mydb.mdf;Integrated Security=True;User Instance=True")) //连接字符串可以写成公共的            {
                con.Open();
                using (SqlCommand cmd = con.CreateCommand())
                {
                     = "Select * from Table1 where username=@un"; //数据库命名不规范
                    cmd.Parameters.Add(new SqlParameter("un", textBox1.Text)); //参数名不规范 如果textBox1.Text如果有空格呢 trim()!
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            string pw = reader.GetString(reader.GetOrdinal("password"));
                            if (pw == textBox2.Text) //pwd
                            {
                                MessageBox.Show("登陆成功！");
                            }
                            else
                            {
                                MessageBox.Show("登录失败！");
                            }
                        }
                        else
                        {
                            MessageBox.Show("用户名不存在！");
                        }
//      //数据库连接为什么不关闭? 释放?
                    }
                }
            }
 
 
 
 
        }
  //注释呢？
        private void label2_Click(object sender, EventArgs e)
        {
 
        }
 //注释呢？
        private void button2_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(
@"Data Source=.\SQLEXPRESS;AttachDBFilename=|DataDirectory|\mydb.mdf;Integrated Security=True;User Instance=True"))
            {
                con.Open();
      
                  
                   string upd = "Insert into Table1(username,password) values('textBox1.Text' ,'textBox2.Text')"; //这么写out 啦
                 
                   SqlCommand mycmd = new SqlCommand(upd,con);
                    MessageBox.Show("注册成功！！");
                //在这里数据库连接为什么不关闭? 释放?
            }
        }
    }
}


[ 本帖最后由 wangnannan 于 2012-1-31 09:55 编辑 ]

楼上分析的很详细。。谢谢

V5
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