如何使用实体模型从数据库保存和检索数据

protected void btnsubmit_Click(object sender, EventArgs e)
{
    dbdataEntities1 dbsdemo = new dbdataEntities1();
    string fname = txtname.Text;
    string lname = txtlastname.Text;
    string email = txtemail.Text;
    string gender = Rbgender.SelectedValue;
    string phoneno = txtphno.Text;
    string role = DropDownList1.SelectedValue;
    string filename = System.IO.Path.GetFileName(Fupload.FileName);
    Fupload.SaveAs(Server.MapPath("Uploads/") + filename);
    tbldata tab = new tbldata();
    tab.filename = filename;
    tab.firstname = fname;
    tab.lastname= lname;
    tab.email = email;
    tab.gender = gender;
    tab.phoneno = Convert.ToInt32(phoneno);
    tab.role = role;
    dbsdemo.tbldatas.Add(tab);
    dbsdemo.SaveChanges();
}

//View.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Napster\documents\visual studio 2015\Projects\WebApplication1\WebApplication1\App_Data\dbdata.mdf;Integrated Security=True;MultipleActiveResultSets=True;Application Name=EntityFramework");
    SqlCommand cmd = new SqlCommand("Select * from tbldata",con);
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    adapter.Fill(ds);
    GridView1.DataSource = ds;
    //dbdataEntities1 dbsdemo = new dbdataEntities1();
    // DataSet query = new DataSet();
    // query=    (from tb in dbsdemo.tbldatas select tb).ToList();
    //GridView1.DataSource = dbsdemo.tbldatas.ToList();
    GridView1.DataBind();
}

//view.ASPX
<asp:ImageField DataImageUrlField="filename" DataImageUrlFormatString="~\Uploads\{0}" HeaderText="Photo" ControlStyle-Height="100" ControlStyle-Width="100" >
    <ControlStyle Height="100px" Width="100px"></ControlStyle>
</asp:ImageField>
    <asp:HyperLinkField DataNavigateUrlFields="id" DataNavigateUrlFormatString="update.aspx?id={0}" DataTextField="id" DataTextFormatString="Edit" HeaderText="Edit" Text="Edit" />
</Columns>

4 个解决方案

#1

update.aspx.cs  
protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                using (datademoEntities db = new datademoEntities())
                {
                    var query = from tbl in db.demotables select new{tbl.Id, tbl.FirstName, tbl.gender, tbl.PhoneNumber, tbl.Role};
                    ddlupdate.DataSource = query.ToList();
                    ddlupdate.DataTextField = "FirstName";
                    ddlupdate.DataValueField = "id";
                    ddlupdate.DataBind();
                    ddlupdate.Items.Insert(0, new ListItem("select"));

                } }


            }
       static int did;
        protected void ddlupdate_SelectedIndexChanged(object sender, 
    EventArgs e)
          {
            did = int.Parse(ddlupdate.SelectedValue);
            using (datademoEntities db = new datademoEntities())
            {
                var query = (from tbl in db.demotables
                             where tbl.Id == did
                             select tbl).First();
                txtname.Text = query.FirstName;
                rbgender.DataTextField = query.gender;

                txtphone.Text = query.PhoneNumber.ToString();

            }
        }

        protected void btnupdate_Click(object sender, EventArgs e)
        {
            string dname = txtname.Text;
            int dphone = int.Parse(txtphone.Text);
            using (datademoEntities db = new datademoEntities())
            {
                demotable tbl = (from row in db.demotables
                                 where
                                 row.Id==did
                                 select row).First();


                 tbl.FirstName = dname;
                tbl.PhoneNumber = dphone;
                db.SaveChanges();
                Response.AddHeader("Refresh", "3;url.display.aspx");
                                 }



        }
    }
    }
display.aspx.cs
  public partial class display : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            datademoEntities db = new datademoEntities();
            var query = (from tbl in db.demotables select tbl).ToList();
            GridView1.DataSource = query;
            GridView1.DataBind();

        }
    }
}

INSERT.apx.cs
 protected void btnsubmit_Click(object sender, EventArgs e)
        {
            datademoEntities dm = new datademoEntities();
            string dname = txtname.Text;
            string drole = ddlrole.SelectedValue;
            string dphone = txtphone.Text;
            string dgender = rbgender.SelectedValue;
            demotable tbl = new demotable();
            tbl.FirstName = dname;
            tbl.Role = drole;
            tbl.PhoneNumber = Convert.ToInt32(dphone);
            tbl.gender = dgender;
            dm.demotables.Add(tbl);
               dm.SaveChanges();

#2

DISPLAY OLD AS PX SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Napster\Documents\Visual Studio 2015\WebSites\demoweb2\App_Data\fundata.mdf;Integrated Security=True");

DISPLAY OLD AS PX SqlConnection con = new SqlConnection（@“Data Source =（LocalDB）\ MSSQLLocalDB; AttachDbFilename = C：\ Users \ Napster \ Documents \ Visual Studio 2015 \ WebSites \ demoweb2 \ App_Data \ fundata.mdf; Integrated Security = True “）;

protected void Page_Load(object sender, EventArgs e)
{

}

protected void Button1_Click(object sender, EventArgs e)
{
    con.Open();
    SqlCommand cmd = con.CreateCommand();
    cmd.CommandType = CommandType.Text;
    cmd.CommandText = "insert into funtable values('"+txtname.Text+"','"+txtcity.Text+"')";
    cmd.ExecuteNonQuery();



    con.Close();
    Response.Redirect("display.aspx");
}

#3

Old method " SelectCommand="SELECT * FROM [demotable]" UpdateCommand="Update [demotable] set [Name]=@name, [city]=@city where [id]=@id" DeleteCommand="delete from [demotable] where [id]=@id">

旧方法“SelectCommand =”SELECT * FROM [demotable]“UpdateCommand =”Update [demotable] set [Name] = @ name，[city] = @ city where [id] = @ id“DeleteCommand =”delete from [demotable]其中[id] = @ id“>

.cs public partial class _Default : System.Web.UI.Page { SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Napster\Documents\Visual Studio 2015\WebSites\Webdemo\App_Data\demodatabase.mdf;Integrated Security=True"); protected void Page_Load(object sender, EventArgs e) {

.cs public partial class _Default：System.Web.UI.Page {SqlConnection con = new SqlConnection（@“Data Source =（LocalDB）\ MSSQLLocalDB; AttachDbFilename = C：\ Users \ Napster \ Documents \ Visual Studio 2015 \ WebSites \ Webdemo \ App_Data \ demodatabase.mdf; Integrated Security = True“）; protected void Page_Load（object sender，EventArgs e）{

}

protected void Submit_Click(object sender, EventArgs e)
{
    con.Open();
   SqlCommand cmd = con.CreateCommand();
    cmd.CommandText = "insert into demotable values('" + txtname.Text + "','" + txtcity.Text + "')";
   cmd.ExecuteNonQuery();
    con.Close();
    Response.Redirect("default.aspx");

}

}

}

#4

Update using connected

使用已连接更新

    protected void btnsubmit_Click(object sender, EventArgs e)
    {

    }
    static int did;

    protected void ddlupdate_SelectedIndexChange
    {
        did = int.Parse(ddlupdate.SelectedValue);
        SqlConnection con = new SqlConnection(@"");
        con.Open();
        SqlCommand cmd = new SqlCommand("Select firstname, lastname, email, 
       gender, role, phoneno, filename from tbldata where Id=" +did, con);
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            txtname.Text = dr.GetString(0);
            txtlastname.Text = dr.GetString(1);
            txtemail.Text = dr.GetString(2);
        }
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        string fname, lastname, email, gender, role, phoneno, filename;
        fname = txtname.Text;
        lastname = txtlastname.Text;
        email = txtemail.Text;
        gender = Rbgender.SelectedValue;
        phoneno = txtphno.Text;
        role = DropDownList1.SelectedValue;
        filename = System.IO.Path.GetFileName(Fupload.FileName);
        Fupload.SaveAs(Server.MapPath("Uploads/") + filename);
        SqlConnection con = new SqlConnection(@"");
        con.Open();
        SqlCommand cmd = new SqlCommand("Update tbldata set firstname=@fname,lastname=@lastname,email=@email,gender=@gender,role=@role,phoneno=@phoneno,filename=@filename where id=@did", con);
        cmd.Parameters.AddWithValue("@firstanme", fname);
        con.Close();
   }
}

}

}