Adding Tables to DataSet in Component

[cjobes]

Hi all,

I'm trying to create a dataset as a component to make it accessable from all
forms. I have used that following code so far in the component designer:

Inherits System.Componen tModel.Componen t
Dim _TryDs As dataSet = NewTry

Public Property dataSet() As dataSet
Get
Return Me._TryDs
End Get
Set(ByVal Value As dataSet)
Me._TryDs = Value
End Set
End Property

Now I have no idea how to add the 2 tables. I have created 2 subs
"createTabl eA" and "createTabl eB" and added the commands
createTableA()
createTableB()
after the initialize component line.

When I try to reference the component the DS is recognized but the tables
are not. I know I'm missing something here. Can anybody help?
Thanks,
Claus

[Cor Ligthert]

Cjobes,

Does this most simple sample that I once made for somebody give you an idea?

\\\
Public Class MyDataset
Inherits DataSet
Sub New()
MyBase.new()
Dim dt As New DataTable("Tabl eKlaus")
Me.Tables.Add(d t)
dt.Columns.Add( "Klaus")
dt.Columns.Add( "Cor")
End Sub
Public ReadOnly Property TableKlaus() As DataTable
Get
Return Me.Tables("Tabl eKlaus")
End Get
End Property
End Class
///

dim ds as new MyDataset
dim dt as datatable = ds.TableKlaus

I hope this gives some ideas?

Cor

"cjobes" <cj****@nova-tech.org> schreef in bericht
news:O1******** *****@TK2MSFTNG P09.phx.gbl...

Hi all,

I'm trying to create a dataset as a component to make it accessable from
all
forms. I have used that following code so far in the component designer:

Inherits System.Componen tModel.Componen t
Dim _TryDs As dataSet = NewTry

Public Property dataSet() As dataSet
Get
Return Me._TryDs
End Get
Set(ByVal Value As dataSet)
Me._TryDs = Value
End Set
End Property

Now I have no idea how to add the 2 tables. I have created 2 subs
"createTabl eA" and "createTabl eB" and added the commands
createTableA()
createTableB()
after the initialize component line.

When I try to reference the component the DS is recognized but the tables
are not. I know I'm missing something here. Can anybody help?
Thanks,
Claus

[cjobes]

Cor,

Thanks a lot. I'm starting to understand this. I assume that your sample
code goes into the component code. I have two more questions:
I need to create 2 tables. Would I do this in the same public class? Also,
could you give me a short sample of what I need to do in a form to create
and instance of the 2 tables?

Actually there is one more question. If I fill the tables with data in one
form and then create an instance of the tables in another form will the data
still be there?

Thanks,
Claus

"Cor Ligthert" <no************ @planet.nl> wrote in message
news:Oc******** ******@TK2MSFTN GP15.phx.gbl...

Cjobes,

Does this most simple sample that I once made for somebody give you an idea?
\\\
Public Class MyDataset
Inherits DataSet
Sub New()
MyBase.new()
Dim dt As New DataTable("Tabl eKlaus")
Me.Tables.Add(d t)
dt.Columns.Add( "Klaus")
dt.Columns.Add( "Cor")
End Sub
Public ReadOnly Property TableKlaus() As DataTable
Get
Return Me.Tables("Tabl eKlaus")
End Get
End Property
End Class
///

dim ds as new MyDataset
dim dt as datatable = ds.TableKlaus

I hope this gives some ideas?

Cor

"cjobes" <cj****@nova-tech.org> schreef in bericht
news:O1******** *****@TK2MSFTNG P09.phx.gbl...

Hi all,

I'm trying to create a dataset as a component to make it accessable from
all
forms. I have used that following code so far in the component designer:

Inherits System.Componen tModel.Componen t
Dim _TryDs As dataSet = NewTry

Public Property dataSet() As dataSet
Get
Return Me._TryDs
End Get
Set(ByVal Value As dataSet)
Me._TryDs = Value
End Set
End Property

Now I have no idea how to add the 2 tables. I have created 2 subs
"createTabl eA" and "createTabl eB" and added the commands
createTableA()
createTableB()
after the initialize component line.

When I try to reference the component the DS is recognized but the tables are not. I know I'm missing something here. Can anybody help?
Thanks,
Claus

[Cor Ligthert]

Claus,

Thanks a lot. I'm starting to understand this. I assume that your sample
code goes into the component code.
You cannot inherit twice however the dataset that is inherited does that
already see in top of this page
http://msdn.microsoft.com/library/de...classtopic.asp
I have two more questions:
I need to create 2 tables. Would I do this in the same public class? Also,
could you give me a short sample of what I need to do in a form to create
and instance of the 2 tables?

Everything you do is up to you, however why not. I showed the things above
in a new sample bellow however how far you go is again up to you. I made a
very simple sample where I made an extra datatable and load a datatable as
method in this extra and showed that table on a datagrid

\\\needs new project with a datagrid on the form
Private Sub Form1_Load(ByVa l sender As Object, _
ByVal e As System.EventArg s) Handles MyBase.Load
Dim ds As New MyDataset
For i As Integer = 0 To 10
ds.KlausTableAd dNew(New Object() {i.ToString, ChrW(i + 65)})
Next
DataGrid1.DataS ource = ds.TableKlaus
End Sub
End Class
Public Class MyDataset
Inherits DataSet
Sub New()
MyBase.new()
Dim dt As New DataTable("Tabl eKlaus")
Me.Tables.Add(d t)
dt.Columns.Add( "Klaus")
dt.Columns.Add( "Cor")
dt = New DataTable("Tabl eCor")
Me.Tables.Add(d t)
dt.Columns.Add( "John")
dt.Columns.Add( "Herfried")
End Sub
Public ReadOnly Property TableKlaus() As DataTable
Get
Return Me.Tables("Tabl eKlaus")
End Get
End Property
Public ReadOnly Property TableCor() As DataTable
Get
Return Me.Tables("Tabl eCor")
End Get
End Property
Public Sub KlausTableAddNe w(ByVal obj As Object())
Dim dr As DataRow = Me.TableKlaus.N ewRow
dr.ItemArray = obj
Me.TableKlaus.R ows.Add(dr)
End Sub
End Class
///

I hope this helps a little bit?

Cor

[Cor Ligthert]

Claus,

I see I deleted with pasting in the sample a part I had answered as well

If I fill the tables with data in one
form and then create an instance of the tables in another form will the
data
still be there?

That class is nothing, the object you create from it holds the data, and
than it is the same as whatever you create.

Assuming this is for a winform (it is not the same for a webform), than
means when you do

Friend ds as new mydataset

somewhere in your project, than it will everywhere in your project be usable
with the information in it. (As long as you do not set it too something
else of course)

I hope this helps?

Cor

[cjobes]

Thanks Cor,

The handling of the additional table is what I thought but you have me
totally confused with "needs new project". I think I need some tutoring to
cut the learning curve in half. I'm happy to pay you for your time. Can you
contact me at cj****@nova-tech.org?

Claus
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:Ol******** ********@TK2MSF TNGP11.phx.gbl. ..

Claus,

Thanks a lot. I'm starting to understand this. I assume that your sample
code goes into the component code.
You cannot inherit twice however the dataset that is inherited does that
already see in top of this page

http://msdn.microsoft.com/library/de...classtopic.asp

>I have two more questions:
I need to create 2 tables. Would I do this in the same public class? Also, could you give me a short sample of what I need to do in a form to create and instance of the 2 tables?

Everything you do is up to you, however why not. I showed the things above
in a new sample bellow however how far you go is again up to you. I made a
very simple sample where I made an extra datatable and load a datatable as
method in this extra and showed that table on a datagrid

\\\needs new project with a datagrid on the form
Private Sub Form1_Load(ByVa l sender As Object, _
ByVal e As System.EventArg s) Handles MyBase.Load
Dim ds As New MyDataset
For i As Integer = 0 To 10
ds.KlausTableAd dNew(New Object() {i.ToString, ChrW(i + 65)})
Next
DataGrid1.DataS ource = ds.TableKlaus
End Sub
End Class
Public Class MyDataset
Inherits DataSet
Sub New()
MyBase.new()
Dim dt As New DataTable("Tabl eKlaus")
Me.Tables.Add(d t)
dt.Columns.Add( "Klaus")
dt.Columns.Add( "Cor")
dt = New DataTable("Tabl eCor")
Me.Tables.Add(d t)
dt.Columns.Add( "John")
dt.Columns.Add( "Herfried")
End Sub
Public ReadOnly Property TableKlaus() As DataTable
Get
Return Me.Tables("Tabl eKlaus")
End Get
End Property
Public ReadOnly Property TableCor() As DataTable
Get
Return Me.Tables("Tabl eCor")
End Get
End Property
Public Sub KlausTableAddNe w(ByVal obj As Object())
Dim dr As DataRow = Me.TableKlaus.N ewRow
dr.ItemArray = obj
Me.TableKlaus.R ows.Add(dr)
End Sub
End Class
///

I hope this helps a little bit?

Cor

[Cor Ligthert]

Claus,

That "needs new project" is only for trying the sample, nothing extra.

:-))

Cor
"cjobes" <cj****@nova-tech.org>

....

Thanks Cor,

The handling of the additional table is what I thought but you have me
totally confused with "needs new project". I think I need some tutoring to
cut the learning curve in half. I'm happy to pay you for your time. Can
you
contact me at cj****@nova-tech.org?

Claus
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:Ol******** ********@TK2MSF TNGP11.phx.gbl. ..

Claus,

> Thanks a lot. I'm starting to understand this. I assume that your
> sample
> code goes into the component code.

You cannot inherit twice however the dataset that is inherited does that
already see in top of this page

http://msdn.microsoft.com/library/de...classtopic.asp

>I have two more questions:
> I need to create 2 tables. Would I do this in the same public class? Also, > could you give me a short sample of what I need to do in a form to create > and instance of the 2 tables?

Everything you do is up to you, however why not. I showed the things
above
in a new sample bellow however how far you go is again up to you. I made
a
very simple sample where I made an extra datatable and load a datatable
as
method in this extra and showed that table on a datagrid

\\\needs new project with a datagrid on the form
Private Sub Form1_Load(ByVa l sender As Object, _
ByVal e As System.EventArg s) Handles MyBase.Load
Dim ds As New MyDataset
For i As Integer = 0 To 10
ds.KlausTableAd dNew(New Object() {i.ToString, ChrW(i + 65)})
Next
DataGrid1.DataS ource = ds.TableKlaus
End Sub
End Class
Public Class MyDataset
Inherits DataSet
Sub New()
MyBase.new()
Dim dt As New DataTable("Tabl eKlaus")
Me.Tables.Add(d t)
dt.Columns.Add( "Klaus")
dt.Columns.Add( "Cor")
dt = New DataTable("Tabl eCor")
Me.Tables.Add(d t)
dt.Columns.Add( "John")
dt.Columns.Add( "Herfried")
End Sub
Public ReadOnly Property TableKlaus() As DataTable
Get
Return Me.Tables("Tabl eKlaus")
End Get
End Property
Public ReadOnly Property TableCor() As DataTable
Get
Return Me.Tables("Tabl eCor")
End Get
End Property
Public Sub KlausTableAddNe w(ByVal obj As Object())
Dim dr As DataRow = Me.TableKlaus.N ewRow
dr.ItemArray = obj
Me.TableKlaus.R ows.Add(dr)
End Sub
End Class
///

I hope this helps a little bit?

Cor

[cjobes]

Thanks again Cor,

From your response I assume that you are not interested in making some
"tutor money". If you change your mind, you have my email.

I will try your suggestions tonight. Hopefully I understood everything
right. I'm a network guy with some experience in VB, so it will be very
interesting to say the least.

Thanks again, I really appreciate your patient help.

Claus
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:u8******** ******@TK2MSFTN GP15.phx.gbl...

Claus,

I see I deleted with pasting in the sample a part I had answered as well

If I fill the tables with data in one
form and then create an instance of the tables in another form will the
data
still be there?
That class is nothing, the object you create from it holds the data, and
than it is the same as whatever you create.

Assuming this is for a winform (it is not the same for a webform), than
means when you do

Friend ds as new mydataset

somewhere in your project, than it will everywhere in your project be

usable with the information in it. (As long as you do not set it too something
else of course)

I hope this helps?

Cor

[cjobes]

Cor,

Sorry to be so stupid but I must still be doing something wrong. I created
the component and defined the tables. I then created an instance in form1
and manipulated the data. As a test I brought a DataGrid up in form1 and it
displays the data correctly.
I created a second form (SearchResult) with a DataGrid(Result Grid) and added
the following code:

Dim ds As GlobalDS.MyData set
Dim dt As DataTable = ds.tbSelect

Private Sub SearchResult_Lo ad(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Me.ResultGrid.D ataMember = "dt"
Me.ResultGrid.D ataSource = ds
End Sub

On form1 I added the code:
Dim frmResults As New SearchResult()
frmResults.Show Dialog()

When I run Debug the program stops at:
Dim dt as DataTable=ds.tb Select
with an error "Object reference not set to an instance of an object"

What am I doing wrong?

Claus
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:u8******** ******@TK2MSFTN GP15.phx.gbl...

Claus,

I see I deleted with pasting in the sample a part I had answered as well

If I fill the tables with data in one
form and then create an instance of the tables in another form will the
data
still be there?
That class is nothing, the object you create from it holds the data, and
than it is the same as whatever you create.

Assuming this is for a winform (it is not the same for a webform), than
means when you do

Friend ds as new mydataset

somewhere in your project, than it will everywhere in your project be

usable with the information in it. (As long as you do not set it too something
else of course)

I hope this helps?

Cor

[Cor Ligthert]

Claus,

What I cannot see is if Global.Dataset is an object or the class itself.
When it is the class or a member of that than it has to be probably
dim ds as "new" GlobalDS.MyData set

I hope this helps?

Cor

"cjobes" <cj****@nova-tech.org>

Sorry to be so stupid but I must still be doing something wrong. I created
the component and defined the tables. I then created an instance in form1
and manipulated the data. As a test I brought a DataGrid up in form1 and
it
displays the data correctly.
I created a second form (SearchResult) with a DataGrid(Result Grid) and
added
the following code:

Dim ds As GlobalDS.MyData set
Dim dt As DataTable = ds.tbSelect

Private Sub SearchResult_Lo ad(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Me.ResultGrid.D ataMember = "dt"
Me.ResultGrid.D ataSource = ds
End Sub

On form1 I added the code:
Dim frmResults As New SearchResult()
frmResults.Show Dialog()

When I run Debug the program stops at:
Dim dt as DataTable=ds.tb Select
with an error "Object reference not set to an instance of an object"

What am I doing wrong?

Claus
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:u8******** ******@TK2MSFTN GP15.phx.gbl...

Claus,

I see I deleted with pasting in the sample a part I had answered as well

>
> If I fill the tables with data in one
> form and then create an instance of the tables in another form will the
> data
> still be there?
>

That class is nothing, the object you create from it holds the data, and
than it is the same as whatever you create.

Assuming this is for a winform (it is not the same for a webform), than
means when you do

Friend ds as new mydataset

somewhere in your project, than it will everywhere in your project be

usable

with the information in it. (As long as you do not set it too something
else of course)

I hope this helps?

Cor