Excel to data base in asp.net C#

protected void Button2_Click(object sender, EventArgs e)

    {

        //SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\projects\importexcelfile\App_Data\Database.mdf;Integrated Security=True;User Instance=True");

        //SqlCommand cmd = new SqlCommand("insert into demo values '" + +"'", con);

            string ConStr = "";  

            string ext = Path.GetExtension(FileUpload1.FileName).ToLower();  

            string path = Server.MapPath("~/excel/"+FileUpload1.FileName);  

            FileUpload1.SaveAs(path);  

            Label1.Text = FileUpload1.FileName ;  

            if (ext.Trim() == ".xls")  

            {  

              ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\"";  

            }  

            else if (ext.Trim() == ".xlsx")  

            {  

                

                ConStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";  

            }  

             

            string query = "SELECT * FROM [Sheet1$]";  

            OleDbConnection conn = new OleDbConnection(ConStr);  

            if (conn.State == ConnectionState.Closed)  

            {  

                conn.Open();  

            }  

            OleDbCommand cmd = new OleDbCommand(query, conn);   

            OleDbDataAdapter da = new OleDbDataAdapter(cmd);  

            DataSet ds = new DataSet();           

            da.Fill(ds);              

            GridView1.DataSource = ds.Tables[0];              

            GridView1.DataBind();             

            conn.Close();  

        

        }


insert ////


 protected void Button3_Click1(object sender, EventArgs e)
    {
        foreach (GridViewRow g1 in GridView1.Rows)
        {
            if (g1.Cells[1].Text == "rr")
            {
                string connStr1 = (@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\projects\importexcelfile\App_Data\Database.mdf;Integrated Security=True;User Instance=True");
                SqlConnection con1 = new SqlConnection(connStr1);
                SqlCommand cmd1;
                cmd1 = new SqlCommand("insert into demo2(id,name,mobile,address) values ('" + g1.Cells[0].Text + "','" + g1.Cells[1].Text + "','" + g1.Cells[2].Text + "','" + g1.Cells[3].Text + "')", con1);
                con1.Open();
                cmd1.ExecuteNonQuery();
                con1.Close();
            }
            else
            {
                string connStr = (@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\projects\importexcelfile\App_Data\Database.mdf;Integrated Security=True;User Instance=True");
                SqlConnection con = new SqlConnection(connStr);
                SqlCommand cmd;
                cmd = new SqlCommand("insert into demo(id,name,mobile,address) values ('" + g1.Cells[0].Text + "','" + g1.Cells[1].Text + "','" + g1.Cells[2].Text + "','" + g1.Cells[3].Text + "')", con);
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
        Label1.Text = "Records inserted successfully";

    }