How to add a "Select All" entry to a Dropdownlist tied to SQLDataSource?

Question

I hvae a dropdownlist tied to a SQLDataSource that returns a list of Categories. Since this is used as part of a search function, how do I add a "Select All" category and ensure that such a selection queries all categories?

Thanks much!!

Mayank Gupta · Answer 1 · 2015-04-10T13:36:07.107

Never Use (AppendDataBoundItems="true")!

<asp:DropDownList ID="drpdwnmodel" DataSourceID="Model_Grid" DataTextField="INI" DataValueField="INI" OnSelectedIndexChanged="drprep_SelectedIndexChanged" OnDataBound="DataBoundbyTest_click" AutoPostBack="true" runat="server">
                           <asp:ListItem Value="All" Text="All"></asp:ListItem>
                        </asp:DropDownList>


  <asp:SqlDataSource ID="Model_Grid" runat="server"
                 ConnectionString="<%$ ConnectionStrings:Testconnectionstring%>"
                 SelectCommand="SELECT DISTINCT INI FROM TestTable where [Column] LIKE '%' + @valuename+ '%'  ORDER BY INI ASC">
                 <SelectParameters>
                     <asp:ControlParameter ControlID="drpdwnmodel" Name="valuename"
                         PropertyName="SelectedValue" Type="String" />
                 </SelectParameters>
             </asp:SqlDataSource>

 protected void DataBoundbyTest_click(object sender, EventArgs e)
    {
        drpdwnmodel.Items.Add("All");
        drpdwnmodel.Items.Insert(0, new ListItem("- Select -", "0"));
    }


protected void drprep_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (drpdwnmodel.SelectedValue.Equals("0"))
        {
            GridView1.DataSourceID = "Test_Grid";
        }
        else {
            if (drpdwnmodel.SelectedValue.Equals("All"))
            {
                GridView1.DataSourceID = "Test_Grid";
            }
            else
            {
                GridView1.DataSourceID = "SqlDataSource1";
            }
        }
        
    }

Why never use (AppendDataBoundItems="true")? – Peanut Apr 10 '15 at 13:35 — Peanut, Apr 10 '15 at 13:35
because, bind data duplicate in dropdown list – Mayank Gupta Jun 12 '15 at 13:26 — Mayank Gupta, Jun 12 '15 at 13:26

score 0 · Accepted Answer · edited May 23 '17 at 12:30

0

I sometimes use sql for this:

select value, description from reference_table
union
select -1, 'Select all'
Order by 2

There is also the way where you add the item in the markup, then set the AppendDataBoundItems="true"

Also, see this similar question and answer

edited May 23 '17 at 12:30

Community

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answered Dec 05 '11 at 00:17

MatthewMartin

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How to add a "Select All" entry to a Dropdownlist tied to SQLDataSource?

2 Answers2