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 }