数据库简单增删改查
时间：2021-07-01 10:21:17
帮助过：5人阅读
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();
}
}
}
数据库简单增删改查
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