namespace 数据库增删改查 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) //登陆(查询) { string user = textBox2.Text; string password = textBox3.Text; SqlConnection coon = new SqlConnection("server=.;database=enter;user=sa;pwd=123"); //连接数据库 coon.Open();//打开数据库 SqlCommand cmd = coon.CreateCommand();//执行查询语句 cmd.CommandText = "select * from enters where username=‘"+user+"‘ and userpass=‘"+password+"‘"; //进行匹配 SqlDataReader dr = cmd.ExecuteReader();//执行查询,将结果反馈给dr if (dr.Read()) { MessageBox.Show("登陆成功"); } else { MessageBox.Show("登陆失败"); } coon.Close(); } private void button3_Click(object sender, EventArgs e) //添加 { string user = textBox2.Text; string password = textBox3.Text; SqlConnection coon = new SqlConnection("server=.;database=enter;user=sa;pwd=123"); coon.Open(); SqlCommand cmd = coon.CreateCommand(); cmd.CommandText = "insert into enters values(‘"+user+"‘,‘"+password+"‘)"; int count = cmd.ExecuteNonQuery();//增删改都用这个 if(count>0) { MessageBox.Show("添加成功"); } coon.Close(); } private void button2_Click(object sender, EventArgs e) //修改 { string code = textBox1.Text; string user = textBox2.Text; string password = textBox3.Text; SqlConnection coon = new SqlConnection("server=.;database=enter;user=sa;pwd=123"); coon.Open(); SqlCommand cmd = coon.CreateCommand(); cmd.CommandText = "update enters set username=‘"+user+"‘ , userpass=‘"+password+"‘ where code="+code; int count = cmd.ExecuteNonQuery(); if(count>0) { MessageBox.Show("修改成功"); } else { MessageBox.Show("修改失败!"); } coon.Close(); } private void button4_Click(object sender, EventArgs e) //删除 { string code = textBox1.Text; SqlConnection coon = new SqlConnection("server=.;database=enter;user=sa;pwd=123"); coon.Open(); SqlCommand cmd = coon.CreateCommand(); cmd.CommandText = "delete from enters where code="+code; cmd.ExecuteNonQuery(); coon.Close(); } } }
时间: 2024-10-12 08:15:35