winform —— 连接数据库SQL Server 2008

using System.Data.SqlClient;命名空间
sqlconnection:数据连接类
sqlcommand:数据库操作类
sqldatareader:读取
  1 using System;
  2 using System.Collections.Generic;
  3 using System.ComponentModel;
  4 using System.Data;
  5 using System.Data.SqlClient;
  6 using System.Drawing;
  7 using System.Linq;
  8 using System.Text;
  9 using System.Windows.Forms;
 10 
 11 namespace WindowsFormsApplication7
 12 {
 13     public partial class Form1 : Form
 14     {
 15         public Form1()
 16         {
 17             InitializeComponent();
 18         }
 19 
 20         private void button1_Click(object sender, EventArgs e)
 21         {
 22             string username = textBox1.Text;
 23             string upass = textBox2.Text;
 24 
 25             //第一步：连接到数据库
 26             SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=");
 27             conn.Open();
 28             //第二步：写执行语句
 29             SqlCommand cmd = conn.CreateCommand();//通过conn创建sqlcommand对象
 30             cmd.CommandText = "select *from users where uname='"+username+"' and upass='"+upass+"'";
 31             SqlDataReader dr = cmd.ExecuteReader();//执行查询，返回sqldatareader对象
 32             if (dr.Read())
 33             {
 34                 MessageBox.Show("登陆成功！");
 35             }
 36             else
 37             {
 38                 MessageBox.Show("登陆失败！");
 39             }
 40 
 41             conn.Close();
 42         }
 43 
 44         private void button2_Click(object sender, EventArgs e)
 45         {
 46             //添加数据到数据库
 47             string username = textBox1.Text;
 48             string upass = textBox2.Text;
 49 
 50             //第一步：连接到数据库
 51             SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=");
 52             conn.Open();
 53             SqlCommand cmd = conn.CreateCommand();
 54             cmd.CommandText = "insert into users values('"+username+"','"+upass+"')";
 55             int count=　cmd.ExecuteNonQuery();//增删改
 56             if (count > 0)
 57             {
 58                 MessageBox.Show("添加成功！");
 59             }
 60             else
 61             {
 62                 MessageBox.Show("添加失败！");
 63             }
 64             conn.Close();
 65         }
 66 
 67         private void button3_Click(object sender, EventArgs e)
 68         {
 69             string code = textBox3.Text;
 70             string uname = textBox1.Text;
 71             string upass = textBox2.Text;
 72             //第一步：连接到数据库
 73             SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=");
 74             conn.Open();
 75             SqlCommand cmd = conn.CreateCommand();
 76             cmd.CommandText = "update users set uname='"+uname+"',upass='"+upass+"' where code="+code;
 77             int count=cmd.ExecuteNonQuery();
 78             if (count > 0)
 79             {
 80                 MessageBox.Show("修改成功！");
 81             }
 82             else
 83             {
 84                 MessageBox.Show("修改失败！");
 85             }
 86             conn.Close();
 87         }
 88 
 89         private void button4_Click(object sender, EventArgs e)
 90         {
 91             string code = textBox3.Text;
 92             SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=");
 93             conn.Open();
 94             SqlCommand cmd = conn.CreateCommand();
 95             cmd.CommandText = "delete from users where code="+code;
 96             cmd.ExecuteNonQuery();
 97             conn.Close();
 98         }
 99 
100         private void Form1_Load(object sender, EventArgs e)
101         {
102 
103         }
104     }
105 }
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