Problems in Dataset Update - Visual Basic Discussion Boards

May be there is no data in table Poke tongue | ;-P

Please try assigning cmd.ExecuteReafder to a DataReader and binding the DataReader to the grid. I think this may help.

Hello madam,
Dim con As New SqlConnection("database=deltadatabase;user id=sa;pwd=sa;server=localhost")
con.Open()
Dim cmd As New SqlCommand("select * from tbl_adminlogin", con)
DataGridView1.DataSource = cmd.ExecuteReader,

There is a problem in 4th line of ur code. Because ExecuteReader is need to open always upto the end. And the important thing is reader need to read continusly. but u did only one time ExecuteReader. To upload the value to datgrid the following code is enough...

Dim con As New SqlConnection("database=deltadatabase;user id=sa;pwd=sa;server=localhost")
Dim cmd As New sqldataadapter("select * from tbl_adminlogin", con)
dim dset as new dataset
cmd.fill(dset,"Tbl")
DataGridView1.DataSource =dset.table(0)

Pls reply wat ever u go...............

Senthil S
Software Engineer

data is there in the table

Sonia Gupta
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Yahoo messengerId-soniagupta1
Love is Friendship and Friendship is Love....

Then try assinging it to dataset and then binding

Is it a WinForms or a ASP.NET application?

In ASP.NET you have to call DataGridView1.DataBind(); after setting the DataSource.

-^-^-^-^-^-
no risk no funk ................... please vote ------>

can we do gprs connection programaticly by vb.net Confused | :confused:

@h3aR

Google for "vb.net gprs".

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

I am having problem with dataset update! I am using a DataAcesTier to access data and update the data and presentation tier is used to do all the manipulation!
Presentation Tier uses DataAcessTier to retrieve the data but when i try to update the database with dataset , NOTING HAPPENS! NO ERROR but NO UPDATES too..
Here is how it goes!!!
I have a class with the name AccessData in my DataAccessTier and it have somehow this sort of code

public sdaMajorDataAdapter as new SqlDataAdapter
public strAllDBTables(50) as string
'strAllDBTables Array is inialized with table names with a sub routine

Public Function CreateDataset() As DataSet
Dim dsMajorDataSet As New DataSet
OpenDbConnection()
' some code for dbcommand and dbconnection variables etc

'For loop used to loop through the table names
For iCounter = 0 to strAllDBTables.length(0) - 1
sdaMajorDataAdapter.Fill(dsMajorDataSet, strAllDBTables(iCounter))
Next
'I have populated the dataset with all the DB tables supposedly
CloseDBConnection()
'this DS is returned to the class from where its accessed
return dsMajorDataSet

End Function
======
Similary in the same class i have a Function for DB update

Public Sub UpdateDataSet(ByVal updateDS As DataSet, ByVal strTableName As String)
OpenDbConnection()
dim dsUpdate as new dataset

'dbCommand.Connection = dbConnection
'dbCommand.CommandText = "Select * from " & strTableName
'sdaUpdate.SelectCommand = dbCommand
'sdaMajorDataAdapter.Fill(dsUpdate, strTableName)
'I have tried to use dataadapter to fill a new dataset and then try to update .no gain

sdaMajorDataAdapter.Update(updateDS, strTableName)
'Which DataAdapter is to be used here ... or do i need to add update queries
'with adapter?, if YES , how to add it?
' There is no error here but NO UPDATES too?

CloseDBConnection()
End Sub

========
'i am accessing these functions in Presentation Tier Class with the name AdminControlPanel Class

'here i have a variable
dim dsControlPanel as new dataset
dim dsRead as new AccessData ' an object of AccessData Class

dsControlPanel = dsRead.CreateDataSet()

' than all the manipulation is done here and after that i return the DS to data access class for updation like this

dsRead.UpdateDataSet(dsControlPanel, "Name of the table to be updated")

'No Error but nothing happens?

i guess i am doing something wrong as to which dataAdapter is to be used?

Thanks for your time

You've told the DataAdapter how to retrieve the columns, well, all of them, from the table, but you never told it how to update the database with changes.

It's much better practice to change your SQL to retrieve the columns to want instead of using the * specifier. This prevent your from making a change to the table schema and breaking your code doing it. In most case, you're end up returning far more data than you actually need, thereby killing your SQL Server performance, and if the dataset is transferred over a network, transferring way too much information and bogging down the network.

How you've written your data layer in not a good idea. You're creating a generic method that returns a DataAdapter, but that DataAdapter doesn't have a clue about what columns it's supposed to

SELECT IdColumn, SomeColumn, SomeOtherColumn FROM TableName

When you create the DataAdpater, you need to tell it how to update the coumns in the tables. To do this, you either have to supply the DataAdapter with the SQL commands for UPDATE, INSERT, and DELETE, or you have to use an SqlCommandBuilder object to do it for you:

Dim conn As New SqlConnection(connectionString)
Dim comm As New SqlCommand("SELECT IdColumn, SomeColumn FROM SomeTable", conn)
Dim da As New SqlDataAdapter(comm)
Dim cb As New SqlCommandBuilder(da)

Dim ds As New DataSet()
da.Fill(ds)

Return ds

Warning: This could be a little off. I wrote it from memory, and I'm half asleep right now...

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

I was just trying to get all the data at front end in dataset! Thats why populated it with all the tables!!!

So, I have to populate my dataset with a single table if i intend to use SqlCommandBuilder! I was trying to use it too but even this was not working, probrably becasue of multiple tables in dataset !!!..

Thanks for the advice sir!

Hello,

I am developing an application that has a menubar. On selecting menu items, I got to open differnet windows (Forms).

This all makes the main program have nothing except the menubar. I want that on clicking any menu item, the respective form comes somewhere on the main window only. On close event of the new form, it gers closed - disappears. So, the new form is inside the main form only. New window is not opened. How do I acheive something like this. If I add a Container in the main window, can I add a form in it. Or Do I have to make the new form as a Panel and add it in some how. If it is a Panel,. then how do I add in the main form. ????

I don't know how do I acheive such a thing in VB.NET. I would appreciate, if anyone can help me out.

Thanks

Terry

hi,
for each "subform" use a "user control".
In the area where you want the subform to appear add a correctly sized panel.

then you can make your user control's parent the panel and add the usercontrol to the panels controls collection.
when you want to use a different usercontrol just remove the original from the panels control collection and add the new one.

a new user control can be added to a solution by right clicking on the solution in the solution explorer and doing an Add new Item (vs2005)

select a usercontrol and then you will get a screen you can add components to.

when you are done
at the menu button click event you can do something like (VB pseudocode)

dim myUc as UserControl = new UserControl
myUC.parent = parentpanel
parentpanel.controls.add myUc
..
dont forget to remove the old UC fromthe parentpanel collection , otherwise it will still try and display and its z-order may be higher than the new one so it will be "above" it

hope this helps
Martin

life is a bowl of cherries
go on take a byte

Thanks Martin & TDDragon.

I tried working with both & Both are good solutions. I prefer only 1 control per screen - in that scenario UC is best. I also need to have a Report and a form with Letter templates, RichTextBox to write letter. Will UC be able to handle this? Also will UC be able to manage with DB, as I got to work with DB a lot.

In MDI, can I ahve control over opening N number of forms. Like if same form is opened, I can just bring it to front but if I want to open only 2 forms max at a time. Is it possible.

Please guide me accordingly, so I can finalize which o choose and start working on it at the earliest.

Thanks

Terry

Hi,
a UC is in effect a form in the designer
just drag and drop what you need.

as far as scope is concerned a textbox in a uc is addressed from outside the UC in this way:

dim myuc as MYUC = new MYUC
myuc.Texbox.Text = "text"

but all controls that go in a form , goes into a uc

martin

life is a bowl of cherries
go on take a byte

with UC you should be able to do all the things you want (works pretty much the same as form)

to have control over openening number of forms in mdi you can do it like following:

when openen a form (user clicked to open it)
first check if the form already exist

iterate true the mdichildren collection of you're main form and if you find a form of the same type as the one that needs to be opened just put that form on top (property bringtofront or something)
of you want to be able to open max2 forms do the same but use counter. then after you iterated true the forms look at counter

dim counter as integer = 0
for each f as form in frmmain.mdichildren
if f.gettype.equals(gettype(frmsubformthatneedstobeopened)) then
counter =+1
end if
next
if counter <2 then
open new form
else
'do something
end if

hope this helps

look at the mdiparent property of a form
it will do excactly what you want

you can add a form to you're main form as follow

mnuclick

dim frm as new form1
frm.mdiparent = me
frm.show

-- modified at 4:53 Thursday 9th August, 2007

this does require that you put the mdiproperty (at design) of your main form to true

Hi,

I think Control.SetTopLevel() method is part of the solution when applied to a form.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

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Like Luc said, you can change a form so it behaves move like a control. Have you ever looked at the inheritance tree for the Form class? It derives from Control. So, it's very easy to treat a form just like it was a control. All you have to do is change one little property:

Dim myNewForm As New WhatEverForm
myNewForm.TopLevel = False
myNewForm.Location = New Point(30, 30)
Me.Controls.Add(myNewForm)

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Thanks All of you.

You all have helped me decide which and what type should I use.
According to you all, I hace used UserControl and Form too. Like Luc and Dave said, I am displaying my form as a Control. If user opens another form, the first one is only active until user closes it, the second soesn't come on top. Just needed to add 1 line, which I was wondering you guys have missed out.

cd = New CustomerData()
cd.TopLevel = False
cd.SetBounds(0, 30, cd.Width(), cd.Height())
Me.Controls.Add(cd)
cd.Show()

Thanks a lot to all of you for your devotion, interest and guidance. I highly appreciate your help. I have voted all of you 5 points.

Thanks

Terry

Hi all
I need to move a control in my program

?????? wat's it about.

do you mean a usercontrol or a standard control??

-- modified at 4:54 Thursday 9th August, 2007

if you mean usercontrol provide me with an email and I'll mail you a example project I just created for someone else
I can't post it here and the code to long
You can mail me from this site (use email instead of reply)

Is this[^] what you're talking about?

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Hi

i am new to vb.net, i develop a project in vb.net(.net version 2005) with some crystal report and i am using some .dll files for project.

i create a setup file for that project and installed in another PC , it doesnt contain .net, when i run the project it throws an error in the crystal report.But the forms are running without error, but the crystal report throws the following error "The type initializer for 'CrystalDecisions.CrystalReports.Engine.ReportDocument' threw an exception"

please help me

Karthik

Is Crystal Reports installed on the target machine ?

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )