using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace 实验
{
public partial class Form1 : Form
{
static string connString = @"Data Source=DESKTOP-SFFEEKC\SQLEXPRESS;Initial Catalog=学生信息表;Integrated Security=SSPI";
SqlConnection conn = new SqlConnection(connString);
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Table_2 where 班级='" + comboBox1.Text + "'", conn);
DataTable dt = new DataTable();
SqlCommandBuilder cmd = new SqlCommandBuilder(da);
da.Update(dt);
MessageBox.Show("更新成功");
conn.Close();
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
conn.Open();
string strQuery = "SELECT * FROM Table_2 where 班级='" + comboBox1.Text + "'";
SqlCommand command = new SqlCommand(strQuery, conn);
SqlDataAdapter da = new SqlDataAdapter(strQuery, conn);
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
conn.Close();
}
}
}
大神们帮我看看,为什么我更新了后,只改变了控件上的数据,并没有改变数据库的信息,我想通过这个控件该数据库里的数据