ASP.NET

1-Feb-09 10:39

Hi
I am very new to this, but I would like to know how to pass a value to AccessDataSource as a parameter in order to update a table.

I have a dropdownlist, and I am able to grab the selected item from the dropdownlist, but I am to get the value into the DataSource and to then update the table.

Can someone explain to me or show me how.

Thanks

sana171-Feb-09 22:20

sana17

1-Feb-09 22:20

you can use : (If you have set NONE to parameter field while configuring datasource)

Accessdatasource1.UpdateParameters.Add("@parametername","parametervalue");

parameter value can be any value you are retrieveing from dropdownlist or textboz or any variable.

there are other ways too, by sessions or querystring etc Smile | :)

Good luck!
regards,
Sana

$@N@

AndyASPVB2-Feb-09 7:55

2-Feb-09 7:55

Hi

thanks for your reply, but I couldn't get it to work. Below is my code snippet:

<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
ProviderName="<%$ ConnectionStrings:NorthwindConnectionString.ProviderName %>"
SelectCommand="SELECT [EmployeeID], [LastName] FROM [Employees]">
</asp:SqlDataSource>

<asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="SqlDataSource1" DataTextField="LastName"
DataValueField="EmployeeID" AutoPostBack="true">
</asp:DropDownList>

<asp:SqlDataSource ID="SqlDataSource3" runat="server"
ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
ProviderName="<%$ ConnectionStrings:NorthwindConnectionString.ProviderName %>"
UpdateCommand="UPDATE [Employees] SET [NotActive]=@NotActive WHERE [EmployeeID]=@EmployeeID">
<UpdateParameters>
<asp:Parameter Name="NotActive" DefaultValue="YES" Type="String" />
<asp:ControlParameter ControlID="DropDownList1" Name="EmployeeID" PropertyName="SelectedValue" />
</UpdateParameters>
</asp:SqlDataSource>
<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False"
DataSourceID="SqlDataSource3" Visible="true">
<Columns>
<asp:BoundField DataField="LastName" HeaderText="LastName"
SortExpression="LastName" />
<asp:BoundField DataField="Active" HeaderText="Active"
SortExpression="Active" />
<asp:BoundField DataField="NotActive" HeaderText="NotActive"
SortExpression="NotActive" />
</Columns>
</asp:GridView>

I have been experimenting by using a parameter tag in order to hold a default value which when the Update query is run the default is passed to the query. Unfortunately, when I check the table it hasn't updated.

What do I need to do fix the problem?

Thanks

sana173-Feb-09 1:06

sana17

3-Feb-09 1:06

ok fine.. well in my last reply there was a mistake there should be no "@" with parameter name.

well u do...
on the UPDATE button or DropDownList_SelectedValueChanged event place the following lines!

SqlDataSource3.UpdateParameters.Add("NotActive","Yes");
SqlDataSource3.UpdareParameters.Add("EmployeeID",DropDownList1.SelectedValue);

I am passing paramters to my datasource in the above way and its working.
Set the placement of these lines as per ur code.

Hope its work!

Good Luck

$@N@

AndyASPVB3-Feb-09 8:51

3-Feb-09 8:51

Sorry, I don't what's a matter with me on something that should be a breeze in the park, but I can't this work. I am not getting any error message, but no value is being passed.

So, I started again and tried to keep it simple. I have one dropdownlist and one button. Below is the markup followed by the VB Code behind:

<asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="AccessDataSource1" DataTextField="LastName"
DataValueField="LastName">
</asp:DropDownList>

<asp:AccessDataSource ID="AccessDataSource1" runat="server"
DataFile="~/Northwind.mdb" SelectCommand="SELECT [LastName] FROM [Employees]">
</asp:AccessDataSource>
<asp:AccessDataSource ID="AccessDataSource2" runat="server"
DataFile="~/Northwind.mdb"
UpdateCommand="UPDATE [Employees] SET [NotActive] = ? WHERE [EmployeeID] = @[EmployeeID]">
</asp:AccessDataSource>
<asp:Button ID="Button1" runat="server" Text="Click Me" />

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
AccessDataSource2.UpdateParameters.Add("NotActive", "YES")
AccessDataSource2.UpdateParameters.Add("EmployeeID", DropDownList1.SelectedValue)
End Sub

Can you please look through, correct and point out to me where I am going wrong!

Thanks

How do you add childnodes to a treeview?

sana174-Feb-09 1:34

sana17

4-Feb-09 1:34

hmmm once i have faced the similar situation while updating records; that there was no error or exception but database is not updated..

try the following inside the button click event:

if(!page.IsPostBack)
{
AccessSource1.UpdateParamters.Add("NoActive","yes");
AccessSource1.UpdateParamters.Add("EmployeeID",DropDownList1.SelectedValue);

}

$@N@

AndyASPVB1-Feb-09 10:35

Image not been displayed from SQL

1-Feb-09 10:35

Hi
I am trying to add a childnode to a treeview in visual basic, but I am able to do so. Can someone give me an example how to do this, please? Below is my method in which I add my parent nodes:

Private Sub PopulateNodes(ByVal dt As DataTable, ByVal nodes As TreeNodeCollection)
Dim var As String

For Each r As DataRow In dt.Rows
Dim tn As New TreeNode()

If r("Active").ToString = "YES" Then

tn.Text = r("LastName").ToString()
tn.Value = r("EmployeeID").ToString()

tn.ImageUrl = ("~/word.png")
ElseIf r("Active").ToString Is Nothing Then

THIS IS WHERE I NEED TO ADD A CHILD NODE

Else

tn.Text = r("LastName").ToString()
tn.Value = r("EmployeeID").ToString()

tn.ImageUrl = ("~/has_store_basic.png")
var = Server.UrlEncode(r("LastName").ToString())

tn.NavigateUrl = ("Results.aspx?Value=" & var)
End If

nodes.Add(tn)

End Sub

Anita_Kamat_inds1-Feb-09 4:38

1-Feb-09 4:38

Any Help will do!!!

I am using this code to display an image from a sql server to an asp.net page:

dr.Read();
{

Response.ContentType = "image/Jpeg";
Response.Expires = 0;
Response.Buffer = true;
Response.Clear();
Response.BinaryWrite((byte[])dr["FileData"]);
Response.End();

}

And all I see is this on the page : System.Web.HttpPostedFile
Cry | :((

Please help me!!!

Colin Angus Mackay1-Feb-09 12:43

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1-Feb-09 12:43

This might be a completely stupid question, but do you actually have an image in the database, or just a series of bytes that translates to the string "System.Web.HttpPostedFile"

Vogon Building and Loan advise that your planet is at risk if you do not keep up repayments on any mortgage secured upon it. Remember that the force of gravity can go up as well as down.

vaghelabhavesh1-Feb-09 13:02

vaghelabhavesh

1-Feb-09 13:02

Or is it possible that the image may have not been saved in the database correctly?

Be careful, there is no Undo Button(Ctrl+Z) in life.

Colin Angus Mackay1-Feb-09 13:04

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1-Feb-09 13:04

crudeCodeYogi wrote:
Or is it possible that the image may have not been saved in the database correctly?

That's what I was implying.

Vogon Building and Loan advise that your planet is at risk if you do not keep up repayments on any mortgage secured upon it. Remember that the force of gravity can go up as well as down.

Anita_Kamat_inds1-Feb-09 16:19

1-Feb-09 16:19

well in the 2005 sql db the field type is image and when I open the table I field reads BinaryData, does that mean the image is corrupted.

Colin Angus Mackay2-Feb-09 8:43

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2-Feb-09 8:43

Anita_Kamat_inds wrote:
well in the 2005 sql db the field type is image

image is deprecated, use varbinary(max) instead.

Anita_Kamat_inds wrote:
when I open the table I field reads BinaryData, does that mean the image is corrupted

No, I'm suggesting you never put the image in there correctly in the first place.

Vogon Building and Loan advise that your planet is at risk if you do not keep up repayments on any mortgage secured upon it. Remember that the force of gravity can go up as well as down.

Anita_Kamat_inds2-Feb-09 9:02

2-Feb-09 9:02

OK, Will try changing the field type, and see what happens. Thanks Man.

Colin Angus Mackay2-Feb-09 9:53

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2-Feb-09 9:53

Going by what you get back in your application, I suspect it was the input of data from your .NET application that was in error.

Vogon Building and Loan advise that your planet is at risk if you do not keep up repayments on any mortgage secured upon it. Remember that the force of gravity can go up as well as down.

Anita_Kamat_inds2-Feb-09 10:01

2-Feb-09 10:01

this is the code I am using to insert the image into the db. I think this line of code has en error:

nBytesRead = theStream.Read(Buffer, 0, BUFFER_SIZE);

the BUFFER_SIZE should be the size of the image,not a const. my guess.

const int BUFFER_SIZE = 255;
int nBytesRead = 0;
Byte[] Buffer = new Byte[BUFFER_SIZE];
StringBuilder strUploadedContent = new StringBuilder("");

Stream theStream = uplTheFile.PostedFile.InputStream;
nBytesRead = theStream.Read(Buffer, 0, BUFFER_SIZE);

while (0 != nBytesRead)
{
strUploadedContent.Append(Encoding.ASCII.GetString(Buffer, 0, nBytesRead));
nBytesRead = theStream.Read(Buffer, 0, BUFFER_SIZE);
}

HttpPostedFile UploadPic = uplTheFile.PostedFile;
int UploadPicLength = UploadPic.ContentLength;
byte[] PicArray = new byte[UploadPicLength];
UploadPic.InputStream.Read(PicArray, 0, UploadPicLength);

OleDbConnection conn = new OleDbConnection(System.Configuration.ConfigurationManager.ConnectionStrings["XXXXXX"].ConnectionString);

OleDbCommand cmd = new OleDbCommand();
cmd.Connection = conn;

string strSQL = "Update tbl set FileData= '" + UploadPic + "' WHERE (ID = 'xcv') ";

Anita_Kamat_inds1-Feb-09 16:06

1-Feb-09 16:06

I have an actual image saved in the DB

Anita_Kamat_inds1-Feb-09 16:08