数据库删除

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

namespace ConnSqlForm
{
public partial class Form3 : Form
{
public Form3()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection("server=.;database=snewdata;user=sa;pwd=");
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "delete from student where xuehao=@xuehao";
cmd.Parameters.Clear();

cmd.Parameters.Add("@xuehao", textBox1.Text.Trim());
conn.Open();
int count = cmd.ExecuteNonQuery();
if (count > 0)
{
MessageBox.Show("删除成功，受影响行数为：" + count.ToString());
}
else
{
MessageBox.Show("删除失败！");
}
conn.Close();
}
}
}