Preloading a SQL databound listview in ASP.NET - c#

I've been looking online for a while and I may not be asking my question right but I can't find what I am looking for.
I have a dropdownlist on a web form that is databound to a SQL select statement that returns 3 items. I appended the list with a blank item at the top so that I am not selecting the other options on page load.
I also have a listview that has a ControlParameter of the DDL.
What I want to do is when the page loads to have all items selected instead of none. Do I need to set Selected to True on each of the items in the list and how would I do that if the information is fetched from a SQL query.
A snippet of the code with the queries:
<asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="SqlDataSourceDockNumber"
DataTextField="DockID" DataValueField="DockID"
AutoPostBack="True" AppendDataBoundItems ="true">
<asp:ListItem Selected="False" Text="" Value=""></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSourceDockNumber" runat="server"
ConnectionString="<%$ ConnectionStrings:MarinaConnectionString %>"
SelectCommand="SELECT DISTINCT [DockID] FROM [Slip]">
</asp:SqlDataSource>
<br />
<asp:SqlDataSource ID="SqlDataSourceAvailSlips" runat="server"
ConnectionString="<%$ConnectionStrings:MarinaConnectionString %>"
SelectCommand="SELECT * FROM [avilableSlips] WHERE ([DockID] = #DockID)">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" Name="DockID"
PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>

Related

How to fill dropdownlist from database based on selected item of another dropdownlist in asp.net

I have a SQL table named doctor search and have 2 dropdownlists one shows expertise of the doctor and i want to fill dropdownlist 2 with the information of those doctor which are related to that expertise section.
This can be done easily if you are using the designer interface.
Try using the below code after making necessary changes (Connection String, Table name and Column name). If that doesn't work, I will share the steps
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:Your Connection String %>" SelectCommand="SELECT [Expertise] FROM [Your Table]"></asp:SqlDataSource>
<asp:DropDownList ID="ddlExpertise" runat="server" DataSourceID="SqlDataSource1" DataTextField="Expertise" DataValueField="Expertise">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:Your Connection String %>" SelectCommand="SELECT [DoctorDetails] FROM [Your Table] WHERE ([Expertise] = #Expertise)">
<SelectParameters>
<asp:ControlParameter ControlID="ddlExpertise" DefaultValue="" Name="Expertise" PropertyName="SelectedValue" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<asp:DropDownList ID="ddlDoctorDetails" runat="server" DataSourceID="SqlDataSource2" DataTextField="DoctorDetails" DataValueField="DoctorDetails">
</asp:DropDownList>

How to set initial value for dropdownlist while using sqldatasource as binding

I have 2 dropdownlist, which are bound to a SQLDataSource and value of 2nd dropdownlist is based on 1st dropdownlist. The problem is that by default dropdownlist are displaying actual values. I put initialvalue in dpsem so, it's working correctly.but when i do same in dpsubj dropdownlist it is showing previous value also.
If I select dpsem--4 then dpsubj should be A,B,C, and if if i select dpsem--6 then dpsubj should be D,E,F. But it is displaying A,B,C,D,E,F...
I am knowing that it is problem related to Autopostback...
<asp:DropDownList ID="dpsem" runat="server" Height="28px"
Width="99px" AutoPostBack="True" DataSourceID="selectsemester"
DataTextField="sem_no" DataValueField="sem_no" AppendDataBoundItems="true">
<asp:ListItem Selected="True" Value="0">-select</asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="dpsubj" runat="server" Height="28px"
Width="99px" AutoPostBack="True" DataSourceID="Selectscode"
DataTextField="scode" DataValueField="scode" AppendDataBoundItems="true">
<asp:ListItem Selected="True" Value="0">-select</asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="Selectscode" runat="server"
ConnectionString="<%$ ConnectionStrings:AttendenceManagementConnectionString %>"
SelectCommand="SELECT DISTINCT [scode] FROM [Semester_Wise_Subject] WHERE (([branch_name] = #branch_name) AND ([sem_no] = #sem_no))">
<SelectParameters>
<asp:ControlParameter ControlID="lbdept" DefaultValue="IT" Name="branch_name"
PropertyName="Text" Type="String" />
<asp:ControlParameter ControlID="dpsem" DefaultValue="6" Name="sem_no"
PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
<asp:SqlDataSource ID="selectsemester" runat="server"
ConnectionString="<%$ ConnectionStrings:AttendenceManagementConnectionString %>"
SelectCommand="SELECT DISTINCT [sem_no] FROM [Batch_year]">
</asp:SqlDataSource>
You should use dpsubj.Items.Clear().. and then again load the filtered data on selectedindexchanged it will first delete all teh previous records in dpsubj dropdown and then use code to load value in dpsubj
I believe you have to create a SelectedIndexChanged event on the first drop down and have that event cause a databind on the second drop down. Also by default if you don't want the second drop down to display data get rid of the default parameter values.
If you are doing anything with ajax you also want to make sure that the first drop down updates the second in your script manager as well.
set AppendDataBoundItems="false" on dpsubj
since you set this property as true, items are not cleared before data binding.

c# pass selected value from dropdownlist to accessdatasource selectparameter

I have an access data source which loads a listbox values. I am trying to pass a parameter to the accessdatasource but I'm not sure what I am doing wrong.
<asp:DropDownList ID="customerName" runat="server">
<asp:ListItem value="69" Text="Danny"></asp:ListItem>
<asp:ListItem value="23" Text="Sarah"></asp:ListItem>
</asp:DropDownList>
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="/App_Data/data.mdb" SelectCommand="SELECT * FROM table WHERE customerID='?'">
<selectparameters>
<asp:ControlParameter Name="customerID" ControlID="customerName" PropertyName="SelectedValue" />
</selectparameters>
<asp:ListBox ID="lstCustomers" runat="server" AutoPostBack="True"
DataSourceID="AccessDataSource1" DataTextField="customerName"
DataValueField="customerID" Width="175px" Height="365px"
onselectedindexchanged="lstCustomers_SelectedIndexChanged"></asp:ListBox>
The list comes back as blank... not sure what I'm doing wrong!
Just to clarify.. This was solved by Richard Deeming, but there's no answer to answer. I'll post the code here
It was solved by removing the single quote marks around the ? parameter in the SQL
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="/App_Data/data.mdb" SelectCommand="SELECT * FROM table WHERE customerID=?">

Get parameters for SelectParameters from another dropdown in c# .net

Does anyone how can I get the parameters for SelectParameters from another dropdown in c# .net?
I check online , and I follow the steps that been told, but it's doesn't seem working for me.
Code:
If I have the following code to retrieved the data for a dropdown:
<asp:DropDownList ID="DropDownVisaType" runat="server" DataSourceID="dsDropDownVisaType" CssClass="dsDropDownVisaType"
DataValueField="VisaTypeID" DataTextField="VisaType" AppendDataBoundItems="true" >
<asp:ListItem></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="dsDropDownVisaType" runat="server" ConnectionString="<%$ ConnectionStrings:SmartStaffConnectionString %>"
SelectCommand="app_visa_type_select" SelectCommandType="StoredProcedure">
</asp:SqlDataSource>
After I select the dropdown, I want to use the VisaTypeID from the dropdown to retrieve data from another dropdown as below:
<asp:DropDownList ID="DropDownVisaTypeSpecific" runat="server" DataSourceID="dsDropDownVisaTypeSpecific" CssClass="dsDropDownVisaTypeSpecific"
DataValueField="VisaTypeSpecificID" DataTextField="VisaTypeSpecific" AppendDataBoundItems="true" >
<asp:ListItem></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="dsDropDownVisaTypeSpecific" runat="server" ConnectionString="<%$ ConnectionStrings:SmartStaffConnectionString %>"
SelectCommand="app_visa_type_specific_select" SelectCommandType="StoredProcedure">
<SelectParameters>
<asp:ControlParameter Property="SelectedValue" ControlID="DropDownVisaType" Name="VisaTypeID" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
Does anyone know what is my code going wrong and how can I make it work?
There is an event SelectedIndexChanged for A dropdown by using that you can get the value of selected Item.
Like below:
protected void DropDownVisaType_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 value = Convert.ToInt32(DropDownVisaType.SelectedItem.Value);
DropDownVisaTypeSpecific.DataSource=Method_Name(Value);
DropDownVisaTypeSpecific.DataBind();
}

how to display items in listbox

How to display list of items in list box while choose a particular item in dropdown list.
example: thiru is a developer he done some modules.
in dropdown list has a list of developers while choose thiru in this list i want to display a what are all the modules completed by thiru that can be listed in listbox
I am using Visual Studio 2008,C# with ASP.Net
Thanks
If your data source is just a List or similar, you can simply do the following:
myListBox.DataSource = myDataSource;
myListBox.DataBind();
If your datasource is a class or list of classes, you need to specify which property to display and which to set as the value.
As above:
myListBox.DataSource = myDataSource;
myListBox.DataTextField = "MyPropertyNameOnMyClass"; //This will be displayed
myListBox.DataValueField = "MyValuePropertyOnMyClass";
myListBox.DataBind();
On the listbox databind your items to a datasource and add a parameter with the value from you drop down list.
This is roughly what you need to do.
<form id="form1" runat="server">
<div>
<asp:ListBox ID="ListBox1" runat="server" DataSourceID="listDataSource"
DataTextField="Field" DataValueField="Field"></asp:ListBox>
<asp:SqlDataSource ID="listDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:XXXX %>"
SelectCommand=
"SELECT [Field] FROM [LisotOfModules] WHERE ([DevID] = #DevID)">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" Name="DevID"
PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
</div>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
DataSourceID="ddlDatasource" DataTextField="DevID"
DataValueField="DevID">
</asp:DropDownList>
<asp:SqlDataSource ID="ddlDatasource" runat="server"
ConnectionString="<%$ ConnectionStrings:XXX %>"
SelectCommand="SELECT [DevID] FROM [Developers]">
</asp:SqlDataSource>
</form>

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