Passing a variable to a dynamic dropdownlist - asp.net

I have 2 dropdownlists, one is State and the second is City. I am trying to create it so, when a user clicks the State, the second dropdownlist is populated with City names from a datatable.
Here is the code
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<%--<cc2:CascadingDropDown ID="CascadingDropDown1" runat="server"> </cc2:CascadingDropDown>--%>
<h1>Live Event Search Engine</h1><br />
State: <asp:DropDownList ID="ddlState" runat="server" AutoPostBack="True" DataSourceID="SqlDataSource1" DataTextField="ST_Code" DataValueField="ST_Code" /><asp:SqlDataSource
ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:dbConnection %>"
SelectCommand="SELECT [ST_Code] FROM [State]">
</asp:SqlDataSource>
City: <asp:DropDownList ID="ddlCity" runat="server" DataSourceID="SqlDataSource2" DataTextField="RS_City" DataValueField="RS_City" /><asp:SqlDataSource
ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:dbConnection %>"
SelectCommand="web_PublicProgramListbyState" SelectCommandType="StoredProcedure">
<SelectParameters>
<asp:SessionParameter Name="State" SessionField="ST_Code" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<asp:Button ID="Submit" runat="server" Text="Submit" />
</asp:Content>
and the code behind is
Public Sub ddlState_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ddlState.SelectedIndexChanged
Me.ddlCity.Items.Clear()
Dim da As New SqlDataAdapter("web_PublicProgramListbyState", New SqlConnection(ConfigurationManager.AppSettings("dbConnection")))
Dim ds As New DataSet
da.Fill(ds, "#State")
da.Dispose()
Me.ddlCity.DataSource = ds.Tables("Products")
Me.ddlCity.DataTextField = "ProductName"
Me.ddlCity.DataValueField = "ProductID"
Me.ddlCity.DataBind()
End Sub
End Class

Looks like you are trying to bring a dataset into this when you already have a SqlDataSource defined. Just modify the parameters of the SqlDataSource and re-bind:
Public Sub ddlState_SelectedIndexChanged(...)
SqlDataSource2.SelectParameters.Clear()
SqlDataSource2.SelectParameters.Add(New Parameter("#State", DbType.String, ddlState.SelectedValue))
ddlCity.DataBind()
End Sub
Edit: Or you can use a ControlParameter referencing ddlState.SelectedValue in SqlDataSource2.SelectParameters as mentioned in another answer. Only trick there is you have to manage your default values carefully so ddlCity only binds when you want it to.

I would change it to a control param and just call the databind. No need to do the fill yourself.
<asp:ControlParameter Name="State" ControlID="ddlState" Type="String" />
and then in the select event just call:
Me.ddlCity.DataBind()
Or if you want to remove the codebehind all together put it in an update panel with a trigger.

I don't see where the ddlState_SelectedIndexChanged event writes the session variable. This is required.

Related

How can I bind a gridview to datasource with dynamic WHERE clause?

I am using Visual Basic for ASP. NET
I know how to populate a gridview with data using only code behind, like this
Dim ds as new datasourse
Dim da as new dataadaptor
Dim con as new SqlConnection
Dim cmd as new SqlCommand
...
Cmd = "select ticketID, problem_text from problems where support_engineer = " & Session("Logged_in_user_id")
...
Gridview1.Datasource = ds
Gridview1.Datasources. DataBind
And that works fines, but my question is: how can i drag and drop a gridview control, and using only the wizard to populate the gridview in design time, how can i define the SELECT statement to only select rows that are related to the logged in user id? See the sql statement above, it uses a session variable that i create in Page_Load event, but how can i use the same logic in design mode? (i don't want to modify the datasource control in code behind)
I looked in youtube and google, and this sites, but all results are simply showing me how to populate the gridview with all rows or with a static condition, not a dynamic one like the one i demonestrated.
Any help is highly appreciated
You could try replacing the form tag in the aspx file
<form id="form1" runat="server">
<div>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:TestConnectionString %>"
SelectCommand="SELECT ticketID, problem_text FROM Tabs WHERE (support_engineer = #Param1)">
<SelectParameters>
<asp:SessionParameter Name="Param1" SessionField="Logged_in_user_id" />
</SelectParameters>
</asp:SqlDataSource>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="True"
DataSourceID="SqlDataSource1">
</asp:GridView>
</div>
</form>
I found out the proper way of binding the gridview to a dynamic session variable, without involving code behind:. Simply use the property <SessionParameter> inside the <SelectParameter>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:TestConnectionString %>"
SelectCommand="SELECT ticketID, problem_text FROM problems
WHERE (support_engineer = #eng_id)
<SelectParameters>
<asp:SessionParameter
Name="eng_id"
SessionField="LoggedInUser"
Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="True"
DataSourceID="SqlDataSource1">
</asp:GridView>

Dynamic query in ASP.Net (WHERE clause in SQLDataSource)

I'm currently trying to loop through an array (two values) and use both values in a query inside the loop. Please see code below. Right now my code doesn't work. I'm trying to populate dynamically the "appType" parameter within the "SelectParameters" tags of the SQLDataSource, but this won't work.
Any suggestion?
<%
Dim appTypes() As String = {"Extranet", "Internet"}
For Each appType As String In appTypes
%>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ProviderName = "<%$ ConnectionStrings:CMS.ProviderName %>"
SelectCommand = "SELECT Applications.Name as AppName, Applications.Abbr as AppAbbr, Types.Name as TypeName, Managers.LastName as LastName, Managers.FirstName As FirstName, Managers.EDKeyEmpID as EDKeyID
FROM Types INNER JOIN (Managers INNER JOIN Applications ON Managers.ID=Applications.Manager) ON Types.ID=Applications.Type
WHERE (Types.Name = #appType)
ORDER BY Types.Name, Applications.Name;"
ConnectionString="<%$ ConnectionStrings:CMS %>">
<SelectParameters>
<asp:Parameter DefaultValue="<%=appType%>" Name="appType" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<asp:Repeater ID="Repeater1" DataSourceID="SqlDataSource1" runat="server">
<ItemTemplate>
<%#Eval("AppName")%> (<%=appType%>)
</ItemTemplate>
</asp:Repeater>
<% Next %>
Modify your SqlDataSource to have an OnSelecting member:
<asp:SqlDataSource ID="SqlDataSource1" runat="server" OnSelecting="OnSelecting"
Reset your SelectParameters back to normal:
<SelectParameters>
<asp:Parameter Name="appType" Type="String" />
</SelectParameters>
Define this method in your code-behind. Implement the logic as required. Here I've shown a dummy value from your Repeater. It'll be up to you to determine how/where that actually comes from (SelectedItem or something similar).
Protected Sub OnSelecting(sender As Object, e As SqlDataSourceSelectingEventArgs) Handles SqlDataSource1.Selecting
e.Command.Parameters("#appType").Value = Repeater1.SomeValue
End Sub

Double Databinding Cascading DropDownList to two SqlDataSources in a FormView

I have two cascading dropdown lists I'm attempting to bind to two separate SqlDataSources each.
These dropdownlists exist in a FormView's EditItemTemplate. Inside the EditItemTemplate two sqldatasource controls exist that populate the department and the jobname. The DeptID and the JobID are the primary keys in those tables. This creates the "cascading effect" between departments and jobs. When a department is selected, only the jobs associated with that department appear.
This piece is working properly.
<asp:FormView ID="frmProfile" runat="server" DataSourceID="sqlDSProfile"
DataKeyNames="EUID" style="margin-top: 0px">
<EditItemTemplate>
<asp:DropDownList ID="ddlDepartments" runat="server" Width="135px"
DataSourceID="sqlDSDepartments"
DataTextField="Department"
DataValueField="DeptID" AutoPostBack="True"
SelectedValue='<%# Bind("CurrentDeptID") %>'
AppendDataBoundItems="true" >
<asp:ListItem></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="ddlJobNames" runat="server" Width="185px"
DataSourceID="sqlDSJobs" DataTextField="JobName" DataValueField="JobID"
SelectedValue='<%# Bind("CurrentJobID") %>'
AppendDataBoundItems="true" >
<asp:ListItem></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="sqlDSDepartments" runat="server"
ConnectionString="<%$ ConnectionStrings:JobsDB %>"
SelectCommand="SELECT tblDepartments.DeptID,
tblDepartments.Department
FROM tblDepartments" />
<asp:SqlDataSource ID="sqlDSJobs" runat="server"
ConnectionString="<%$ ConnectionStrings:JobsDB %>"
SelectCommand="SELECT tblJobs.JobID, tblJobs.JobName FROM tblJobs
INNER JOIN tblDeptsJobs ON tblDeptsJobs.JobID = tblJobs.JobID
WHERE tblDeptsJobs.DeptID = #DeptID" >
<SelectParameters>
<asp:ControlParameter ControlID="ddlDepartments" Name="DeptID"
PropertyName="SelectedValue" />
</SelectParameters>
</asp:SqlDataSource>
</EditItemTemplate>
</asp:FormView>
Outside the formview the SqlDataSource exists that binds all of the information to the Employee table in an update statement. I'm leaving all of the other information in this SqlDataSource even though it's been omitted from the FormView above.
<asp:SqlDataSource ID="sqlDSProfile" runat="server"
ConnectionString="<%$ ConnectionStrings:JobsDB %>"
SelectCommand="SELECT tblEmployee.EUID,
tblEmployee.DateHired,
tblEmployee.LastName,
tblEmployee.HiredLastName,
tblEmployee.FirstName,
tblEmployee.Role,
tblEmployee.JobGrade,
tblEmployee.CurrentDeptID,
tblDepartments.Department,
tblDepartments.DeptID,
tblEmployee.CurrentJobID,
tblJobs.JobName,
tblJobs.JobID,
tblEmployee.CurrentShift,
tblEmployee.JobDate,
tblEmployee.IsDisplaced,
tblEmployee.EligibilityDate
FROM tblEmployee
LEFT OUTER JOIN tblDepartments ON tblEmployee.CurrentDeptID = tblDepartments.DeptID
EFT OUTER JOIN tblJobs ON tblEmployee.CurrentJobID = tblJobs.JobID
WHERE (tblEmployee.EUID = #EUID)"
UpdateCommand="UPDATE [tblEmployee]
SET [tblEmployee].[DateHired] = #DateHired,
[tblEmployee].[LastName] = #LastName,
[tblEmployee].[HiredLastName] = #HiredLastName,
[tblEmployee].[FirstName] = #FirstName,
[tblEmployee].[Role] = #Role,
[tblEmployee].[JobGrade] = #JobGrade,
[tblEmployee].[CurrentDeptID] = #CurrentDeptID,
[tblEmployee].[CurrentJobID] = #CurrentJobID,
[tblEmployee].[CurrentShift] = #CurrentShift,
[tblEmployee].[JobDate] = #JobDate,
[tblEmployee].[IsDisplaced] = #IsDisplaced,
[tblEmployee].[EligibilityDate] = #EligibilityDate
WHERE [tblEmployee].[EUID] = #EUID"
ProviderName="System.Data.SqlClient">
<SelectParameters>
<asp:SessionParameter Name="EUID" SessionField="sProfileEUID" DbType="String" />
</SelectParameters>
<UpdateParameters>
<asp:Parameter Name="DateHired" DbType="Date" />
<asp:Parameter Name="LastName" DbType="String" />
<asp:Parameter Name="HiredLastName" DbType="String" />
<asp:Parameter Name="FirstName" DbType="String" />
<asp:Parameter Name="Role" DbType="String" />
<asp:Parameter Name="JobGrade" DbType="Byte" />
<asp:Parameter Name="CurrentDeptID" DbType="Int32" />
<asp:Parameter Name="CurrentJobID" DbType="Int32" />
<asp:Parameter Name="CurrentShift" DbType="Int32" />
<asp:Parameter Name="JobDate" DbType="Date" />
<asp:Parameter Name="IsDisplaced" DbType="Boolean"/>
<asp:Parameter Name="EligibilityDate" DbType="Date"/>
<asp:SessionParameter Name="EUID" SessionField="sProfileEUID" DbType="String" />
</UpdateParameters>
</asp:SqlDataSource>
The only pieces I can't figure out how to bind are the Departments and the Jobs. Everything else is working. I've tried using the following code in the DropDownList controls...
SelectedValue='<%# Bind("CurrentDeptID") %>'
SelectedValue='<%# Bind("CurrentJobID") %>'
...but these result in errors.
Summary
When the user clicks edit, I need the values in the two dropdownboxes to pull their selectedvalue from the main sqlDSProfile data source, but I need them to be updatable. I've gotten it to the point where I can update and bind the job that an associate belongs to, but because the dropdownlists cascade, when I attempt to change the department the AutoPostBack breaks the binding between sqlDSProfile - CurrentJobID and ddlJobs.
Update
I added tblEmployee.CurrentDeptID and tblEmployee.CurrentJobID to the select statement, and added Bind() statements to the DropDownList controls.
SelectedValue='<%# Bind("CurrentDeptID") %>'
SelectedValue='<%# Bind("CurrentJobID") %>'
The two DropDownLists are now populated with accurate information pulled from the Employee table, showing the department and job that the employee belongs to.
The two DropDownLists are also populated by the two SqlDataSources inside the FormView, giving me options for changing the department and changing the job.
When I change the Job, it works and the employees job is updated.
When I change the Department, it breaks saying DataBinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control.
Close to Done
I removed the data binding from ddlJobs and coded that in the background.
Protected Sub frmProfile_ItemUpdating(sender As Object, e As System.Web.UI.WebControls.FormViewUpdateEventArgs) Handles frmProfile.ItemUpdating
If frmProfile.CurrentMode = FormViewMode.Edit Then
e.NewValues("CurrentJobID") = DirectCast(DirectCast(sender, FormView).FindControl("ddlJobs"), DropDownList).SelectedValue
End If
End Sub
The only piece that's left is building the code for when the ddlDepartments changes.
pseudocode...
' If Item exists in ddlJobs Then
' select item (CurrentJobID)
' else
' select index 0 and make them pick something new
' end if
So Close!
Updated Again
This is the code I've developed to loosely bind this. In the page_load I'm trying to pull the contents of CurrentJobID from sqlDSProfile and check to see if that value exists in ddlJobs. If it does I want to set ddlJobs.SelectedValue = to that CurrentJobID. If it doesn't I want to set the selectedindex to 0 which is a message saying "pick one" or something.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If frmProfile.CurrentMode = FormViewMode.Edit Then
' Need to determine if the CurrentJobID returned in the select statement
' exists in the ddlJobs dropdownlist. If it does, set that to the
' selectedvalue, if not set it to 0 so the user can select a new job.
Dim ddlJobs As DropDownList = frmProfile.FindControl("ddlJobs")
Dim dvProfile As DataView = sqlDSProfile.Select(DataSourceSelectArguments.Empty)
Dim drvProfile As DataRowView = dvProfile(0)
If ddlJobs.Items.FindByValue(drvProfile("CurrentJobID")) Is DBNull.Value Then
ddlJobs.SelectedIndex = 0
Else
ddlJobs.SelectedValue = drvProfile("CurrentJobID")
End If
End If
End Sub
Its returning a null reference exception on the line where I'm checking for dbnull.value
I had a similar issue and found a very simple resolution, (and in c#). Imagine a database with a table Questions, related to category and subcategory tables (which are also related and constrained). When trying to update existing records asp throws an error. This is the solution that I worked out thanks to the information above from Lucretius et al.
Only databind the parent dropdownlist
Find a way to insert the child dropdown selected value on the update event of the datasource.
As:
protected void odseditquestion_Updating(object sender, ObjectDataSourceMethodEventArgs e)
{
//dynamically assign value from ddlsubcategory to odseditquestion on updating event
//you really should not have to do this
DropDownList ddlsubcategory = (DropDownList)fveditquestion.FindControl("ddlsubcategory");
e.InputParameters["subcatid"] = (ddlsubcategory.SelectedValue);
}
It works on my application. Hope it helps somebody, this one cost me half a day, such is asp!!
The problem can be if tlbEmployee columns in the SqlDSProfile in the update statement and field names used by your controls do not match. Other procedures you've followed are right.
SqlDataSource control expects field names it updates to be similar
with those bound to the controls(fields) inside the DataBound control.
The Solution can be: change all the update Parameters to ControlParameters referencing the right control for each one
Update: Wait, I think the problem is your select statement of the SqlDSProfile should contain: CurrentDeptID and CurrentJobID. Try it:
<asp:SqlDataSource ID="sqlDSProfile" runat="server"
ConnectionString="<%$ ConnectionStrings:JobsDB %>"
SelectCommand="SELECT tblEmployee.EUID,
tblEmployee.DateHired,
tblEmployee.LastName,
tblEmployee.HiredLastName,
tblEmployee.FirstName,
tblEmployee.Role,
tblEmployee.JobGrade,
tblDepartments.Department,
tblJobs.JobName,
tblEmployee.CurrentShift,
tblEmployee.JobDate,
tblEmployee.IsDisplaced,
tblEmployee.EligibilityDate
tblEmployee.CurrentDeptID,
tblEmployee.CurrentJobID
FROM tblEmployee
Advice: Test your code portion by portion.
Try the code without the dropdownlist, Test separately
Add the one drop downlist
Use select * from ... in select queries
Avoid ajax when testing
If you make it
Add portions of code portion after portion
at last use the partial updating (ajax)
I have a working solution now, thanks in part to Nuux and a bunch of online research. The tip about the join statement wasn't relevant, but the tip about including "CurrentJobID" and "CurrentDeptID" in my select query was spot on.
In addition to that I had to rework the controls a little. The two cascading dropdownlists are below. The ddlJobs dropdown list behaves like a normal databound control, but it doesn't have the Bind("CurrentJobID") statement I was trying in my original post.
<asp:DropDownList ID="ddlDepartments" runat="server" Width="185px"
DataSourceID="sqlDSDepartments"
DataTextField="Department"
DataValueField="DeptID"
SelectedValue='<%# Bind("CurrentDeptID") %>'
AppendDataBoundItems="true"
AutoPostBack="True" >
<asp:ListItem Text="--Select One--" Value="" />
</asp:DropDownList>
<asp:DropDownList ID="ddlJobs" runat="server" Width="185px"
DataSourceID="sqlDSJobs"
DataTextField="JobName"
DataValueField="JobID"
AppendDataBoundItems="true"
OnDataBinding="ddlJobs_DataBinding" />
The only thing the custom routine "ddlJobs_DataBinding" is doing is adding "--Select One--" as index 0 in the ddlJobs dropdown. I tried this in several places, like page_load, and the databound event of the formview with no success.
Protected Sub ddlJobs_DataBinding(sender As Object, e As System.EventArgs)
Dim ddlJobs As DropDownList = frmProfile.FindControl("ddlJobs")
Dim liSelectOne As New ListItem("--Select One--", 0)
ddlJobs.Items.Clear()
ddlJobs.Items.Insert(0, liSelectOne)
End Sub
The databound event of the formview frmProfile_DataBound event does do some work though. When the user clicks "edit" on the formview to enter editing mode this ensures that the dropdownlist ddlJobs has the correct job selected by default for the profile in question. If the user hasn't been assigned to a job then it defaults to selectedindex 0 which is "--Select One--" set in custom databinding event just above.
Protected Sub frmProfile_DataBound(sender As Object, e As System.EventArgs) Handles frmProfile.DataBound
If frmProfile.CurrentMode = FormViewMode.Edit Then
Dim ddlJobs As DropDownList = frmProfile.FindControl("ddlJobs")
Dim dvProfile As DataView = sqlDSProfile.Select(DataSourceSelectArguments.Empty)
Dim drProfile As DataRow = dvProfile.Table.Rows(0)
If drProfile("CurrentJobID").ToString() = "" Then
ddlJobs.SelectedIndex = 0
Else
ddlJobs.SelectedValue = drProfile("CurrentJobID").ToString()
End If
End If
End Sub
Finally, if the user selects a new job from ddlJobs, that value has to be fed to the database, which the ItemUpdating event of the formview handles.
Protected Sub frmProfile_ItemUpdating(sender As Object, e As System.Web.UI.WebControls.FormViewUpdateEventArgs) Handles frmProfile.ItemUpdating
If frmProfile.CurrentMode = FormViewMode.Edit Then
Dim ddlJobs As DropDownList = frmProfile.FindControl("ddlJobs")
e.NewValues("CurrentJobID") = ddlJobs.SelectedValue
End If
End Sub
Done!

Dropdown list to filter gridview

I would like my gridview to be filtered by the dropdown list I have. It is pulling specific information from the database, so when you choose a value from the dropdown list, it should search through all the records and find only records with the ddl value in them.
The code that I am using in the codebehind for the SelectedIndexChanged is not right though. I get an error message saying 'Value' is not a member of 'Integer'. This is on the line dsCompanyFilter.SelectParameters.Add
It probably has something to do with the gridview not tying to the dropdown list properly, but I am not sure how to fix that code. Please help!
<asp:Content ID="Content2" ContentPlaceHolderID="body" Runat="Server"><br /><br /><br />
<asp:linkbutton id="btnAll" runat="server" text="ALL" onclick="btnAll_Click" />
<asp:repeater id="rptLetters" runat="server" datasourceid="dsLetters">
<headertemplate>
|
</headertemplate>
<itemtemplate>
<asp:linkbutton id="btnLetter" runat="server" onclick="btnLetter_Click"
text='<%#Eval("Letter")%>' />
</itemtemplate>
<separatortemplate>
|
</separatortemplate>
</asp:repeater>
<asp:sqldatasource id="dsLetters" runat="server" connectionstring="<%$
ConnectionStrings:ProductsConnectionString %>"
selectcommand="SELECT DISTINCT LEFT(ProductName, 1) AS [Letter] FROM [Product]">
</asp:sqldatasource>
Filter By Company:<asp:DropDownList ID="ddlCompany" runat="server"
DataSourceID="dsCompanyFilter" DataTextField="CompanyName" DataValueField="CompanyID">
</asp:DropDownList>
<asp:gridview id="gvProducts" runat="server" AutoGenerateColumns="False"
datakeynames="ProductID" datasourceid="dsProductLookup"
style="margin-top: 12px;">
<Columns>
<asp:BoundField DataField="ProductName" HeaderText="ProductName"
SortExpression="ProductName" />
</Columns>
</asp:gridview>
<asp:sqldatasource id="dsProductLookup" runat="server" connectionstring="<%$
ConnectionStrings:ProductsConnectionString %>"
Selectcommand="SELECT ProductID, ProductName FROM [Product] ORDER BY [ProductName]">
</asp:sqldatasource>
<asp:SqlDataSource ID="dsCompanyFilter" runat="server"
ConnectionString="<%$ ConnectionStrings:ProductsConnectionString %>"
SelectCommand="SELECT [CompanyName], [CompanyID] FROM [Company]">
</asp:SqlDataSource>
</asp:Content>
This code filters the results in the gridview by Letter and the Dropdown. The problem is with the dropdown list filtering the gridview.
Protected Sub btnLetter_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim btnLetter As LinkButton = TryCast(sender, LinkButton)
If btnLetter Is Nothing Then
Return
End If
dsProductLookup.SelectCommand = [String].Format("SELECT ProductID, ProductName
FROM [Product]
WHERE ([ProductName] LIKE '{0}%')
ORDER BY [ProductName]", btnLetter.Text)
End Sub
This is the part that has the problem. I now get the error, must declare the scalar variable #CompanyID
Protected Sub ddlCompany_SelectedIndexChanged(ByVal sender As Object, ByVal e As
System.EventArgs) Handles ddlCompany.SelectedIndexChanged
dsProductLookup.SelectCommand = "SELECT ProductName, CompanyID, CompanyName
FROM Product, Company
WHERE CompanyID = #CompanyID
ORDER BY ProductName"
dsProductLookup.SelectParameters.Add("#CompanyID", DbType.Int32,
ddlCompany.SelectedValue)
End Sub
Deleted my previous answer.
Actually try the following :
dsProductLookup.SelectParameters.Add("#ProductID",
DbType.Int32, ddlCompany.SelectedValue)
No assignment to value as it is part of the Add. Noticed this when I tried to compile a test of my previous answer which didn't work.
EDIT: I tried the above code and it worked (did it in C#) but changed it to use DbType.Int32 for second param.
dsProductLookup.SelectParameters.Add("#ProductID", SqlDbType.Int).Value
It looks to me ilke the .Add() method is returning an int, to which .Value is not a property.
Confirmed it to make sure:
This is from the MSDN: Should help.
http://msdn.microsoft.com/en-us/library/w1kdt8w2.aspx
I'm guessing here -- I don't use SqlDataSources -- but it looks like SelectParameters.Add takes three parameters. What happens when change this:
dsProductLookup.SelectParameters.Add("#ProductID", SqlDbType.Int).Value = ddlCompany.SelectedValue
to this:
dsProductLookup.SelectParameters.Add("#ProductID", DbType.Int32, ddlCompany.SelectedValue)
or this:
dsProductLookup.SelectParameters.Add("#ProductID", TypeCode.Int32, ddlCompany.SelectedValue)

asp.net dropdownlist

I have two dropdownlists for a search, the 1st list is for the city and the second is for the area within the selected city. I would like to add a default value in the 2nd dropdownlist that will search ALL of the areas by default unless a specific area is selected from the list that contains the areaID for a specific search.
<asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="SqlDataSource1" DataTextField="cityName" AutoPostBack="true" DataValueField="cityID">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT * FROM [Cities]"></asp:SqlDataSource>
<asp:DropDownList ID="DropArea" runat="server" DataSourceID="SqlArea"
DataTextField="areaName" DataValueField="areaID">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlArea" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT * FROM [area] WHERE ([cityID] = #cityID)">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" DefaultValue="0" Name="cityID"
PropertyName="SelectedValue" Type="Int16" />
</SelectParameters>
</asp:SqlDataSource>
<asp:Button ID="Button1" runat="server" Text="Search" onclick="Button1_Click" />
Bind the second from code behind. Create a data table and insert the Select text at the begining and bind the datatable to the DDL.
DataTable dt =
DataRow dr = dt.NewRow()
dr["areaName"] = "All";
dr["SqlArea"] = "All";
tbldata.Rows.InsertAt(dr,0);
DropArea.DataSource = dt;
DropArea.DataBind();
You can try to add for second dropdownlist OnDataBound="DropArea_DataBound" event.
And use in code:
protected void DropArea_DataBound(object sender, EventArgs e)
{
DropArea.Items.Insert(0, new ListItem() {Value = "-1", Text = "ALL"});
}
And then when you handle click event, check:
var value = DropArea.SelectedItem.Value;
if(string.equals(value, '-1')
{
use your logic here
}
Hope it will help with your problem.
Best regards, Dima.
Chris,
I got the idea below from an answer HERE, but basically you want to modify your query to be in the form of the following:
Your Original:
SELECT * FROM [Cities]
Change To:
SELECT City FROM [Cities]
UNION ALL
SELECT 'ALL'
Old question, but you never found an answer.

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