Select dropdownlist value and display gridview from different tables ASP.NET

asp.netdrop-down-menu

I create web application. I add drop down list. I connect list with Names of Tables Categories. for example 1, 2, 3. When I select value 1 it should be created grid view populated with data from Table 1. When I select 2 create grid view populated with data from Table 2..
I connect tables in the SQL database. PrimaryKey Category ID, foreign key1, foreign key2 approprietly.

I know how to populate grid view by select value in the drop down list, but the values from one table. In this case I have 4 tables and I don't know how to realise that. Is there somebody who can help me? by some tutorial, or piece of code? thanks

Best Answer

try this...

aspx page:

<body>
    <form runat="server">
    <asp:DropDownList runat="server" ID="ddlDb" AutoPostBack="True" OnSelectedIndexChanged="ddlDb_SelectedIndexChanged">
        <asp:ListItem Text="-- Select --" Value=""></asp:ListItem>
        <asp:ListItem Text="Students" Value="Students"></asp:ListItem>
        <asp:ListItem Text="Classes" Value="Classes"></asp:ListItem>
    </asp:DropDownList>
    <asp:GridView ID="GridView1" runat="server">
    </asp:GridView>
    </form>
</body>

aspx.cs:

protected void ddlDb_SelectedIndexChanged(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(ddlDb.SelectedValue))
    {
        var dbPath = Server.MapPath(@"\App_Data\Database1.mdf");
        var scon = "Data Source=.\\SQLEXPRESS;AttachDbFilename='" + dbPath + "';Integrated Security=True;User Instance=True";
        var cmd = "select * from " + ddlDb.SelectedValue;

        var dt = new DataTable();
        var da = new SqlDataAdapter(cmd, scon);
        da.Fill(dt);

        GridView1.DataSource = dt;
        GridView1.DataBind();                
    }
}

enter image description here

For MVC v5.1 use Html.EnumDropDownListFor

@Html.EnumDropDownListFor(
    x => x.YourEnumField,
    "Select My Type", 
    new { @class = "form-control" })

For MVC v5 use EnumHelper

@Html.DropDownList("MyType", 
   EnumHelper.GetSelectList(typeof(MyType)) , 
   "Select My Type", 
   new { @class = "form-control" })

For MVC 5 and lower

I rolled Rune's answer into an extension method:

namespace MyApp.Common
{
    public static class MyExtensions{
        public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                select new { Id = e, Name = e.ToString() };
            return new SelectList(values, "Id", "Name", enumObj);
        }
    }
}

This allows you to write:

ViewData["taskStatus"] = task.Status.ToSelectList();

by using MyApp.Common

Ruby-on-rails – nested drop down box and multi-select box based on each drop down in rails

I would need a bit more info, especially some code examples to really help you. However here is some resources to get you started. When you have written something, then please come back and i/others can help you further :)

Railscasts #88 - Dynamic select menus (revised) - This railscast explains how to make a dynamic select/dropdown menu, fx changing the materials when selecting a category.
Railscasts #196 - Nested model form (revised) - This railscast shows how to dynamically add associated records with accepts_nested_attributes_for. This is not necessarily important to you but will at least help you to understand how to create a multi record form.

Update: How to dynamically populate a dropdown/select menu

Ok so what you want is to have a select menu (also called dropdown menu) of apparels, that updates each time you select a category (in a multiple select menu). To this can you use the method shown in Railscasts #88 - Dynamic select menus (revised), but let me explain more here:

First we want to create the view:

<%= form_for @object do |f| %> # don't know what your form is for, but you can just change it accordantly 
  <%= f.collection_select(:category_ids, Category.all, :id, :name, {}, {:multiple => true, :id => 'category_select'})
  <%= f.grouped_collection_select :apparel_id, Category.all, :apparels, :name, :id, :name, {}, {:id => 'appare} %>
<% end %>

Then we add some javascript in the assets directory:

jQuery ->
  $('#apparel_select').hide() # hide the select menu
  apparels = $('#apparel_select').html() # get all the apparels in groups (the option and optgroup tags)

  $('#category_select').change -> # when selecting/deselecting a category, should we update the apparels select menu
    categories = $('#sel9UX :selected').map -> # find the selected categories
      $(this).text() 

    options = {} 
    $.each categories, (index, value) -> # find all the optgroups that should be shown
      options[value] = $(apparels).filter("optgroup[label='#{value}']")

    $('#apparel_select').html("") # empty the select menu
    $.each options, (key, value) -> # add each category group we have selected
      $('#apparel_select').append(value)

    $('#apparel_select').show() # show the select menu again

This is written in CoffeeScript with jQuery. If you don't use CoffeeScript, then write a comment and i will try to write it in the normal javascript syntax.

Best Answer

Related Solutions

C# – How to create a dropdownlist from an enum in ASP.NET MVC

For MVC v5.1 use Html.EnumDropDownListFor

For MVC v5 use EnumHelper

For MVC 5 and lower

Ruby-on-rails – nested drop down box and multi-select box based on each drop down in rails

Update: How to dynamically populate a dropdown/select menu

Related Topic