使用datatable来链接数据库

一般都放在button1控件上，datatable无需添加列，无需做任何改动

  private void button1_Click(object sender, EventArgs e)
        {
            string connstr = "Data Source=LAPTOP-5KORIHAE;Initial Catalog=testdp1;Integrated Security=True";
            DataTable dt = new DataTable();
            using (SqlConnection sc = new SqlConnection(connstr))
            {
                sc.Open();
                string sql = " select* from 蜀国";
                SqlDataAdapter sdr = new SqlDataAdapter(sql, sc);
                sdr.Fill(dt);
            }
            this.dataGridView1.DataSource = dt;
        }

在button控件上写列

点击button1控件才会出现这些数据表

  private void button1_Click(object sender, EventArgs e)
        {
            string connstr = "Data Source=LAPTOP-5KORIHAE;Initial Catalog=testdp1;Integrated Security=True";
            DataTable dt = new DataTable();
            using (SqlConnection sc = new SqlConnection(connstr))
            {
                sc.Open();
                string sql = " select* from 蜀国";
                SqlDataAdapter sdr = new SqlDataAdapter(sql, sc);
                sdr.Fill(dt);
            }
            this.dataGridView1.DataSource = dt;
        }

注意：链接数据库时：

SqlConnection sc = new SqlConnection(connstr)
前缀加上：
using System.Data.SqlClient;

#注意 如果出现：obj中文件不能复制到bin中问题时，则可以重启点脑，或者改以一下项目的名称；