How to save and retrieve data from database using Entity Model

问题内容:

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>

问题评论:

5  
You should edit the question and give us details on what you are trying and what and, hopefully why, it is failing.
    
you use the adapter.Fill(ds) method but never assign the DataView.DataSource = ds;

答案:

答案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();

答案评论:

    
DISPLAY OL ASPX
– Zeletron tech
20 hours ago
    
SqlConnection con = new SqlConnection(@”Data Source= 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”); }
– Zeletron tech
20 hours ago

答案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”);

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");
}

答案评论:

答案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”>

.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");

}

}

答案评论:

答案4:

Update using connected

    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();
   }
}

}

答案评论:

原文地址:

https://stackoverflow.com/questions/47740120/how-to-save-and-retrieve-data-from-database-using-entity-model

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