How to trap DBNull?

[cjobes]

Hi all,

I have a date field in a temp table as part of a DataSet. In some records
the value is DBNull. how can I trap the error with
if dtTemp("When") = ??? Then.....

Thanks,

Claus

[Lucas Tam]

Re: How to trap DBNull?

"cjobes" <cjobes@nova-tech.org> wrote in news:OAvLiZa1EH A.324
@TK2MSFTNGP10.p hx.gbl:
[color=blue]
> Hi all,
>
> I have a date field in a temp table as part of a DataSet. In some records
> the value is DBNull. how can I trap the error with
> if dtTemp("When") = ??? Then.....[/color]


If dtTemp("When") is system.dbnull.v alue then
Msgbox("oops dbnull!")
end if



--
Lucas Tam (REMOVEnntp@rog ers.com)
Please delete "REMOVE" from the e-mail address when replying.

http://members.ebay.com/aboutme/coolspot18/

[cjobes]

Re: How to trap DBNull?

Thanks, that worked.

Now that the project doesn't time out anymore, I found another problem.
Where the dtTemp("When") column is not DBNull I need to replace the value of
another column (dtTemp("When2" ) with a value of a specific variable.
Rows.Add doesn't work (although the books say that if the PK value for the
record is already there it would replace the data) and there isn't anything
like "change" or "replace". How can I do this?

Thanks,

Claus


"Lucas Tam" <REMOVEnntp@rog ers.com> wrote in message
news:Xns95AFC39 7C92C5nntproger scom@140.99.99. 130...[color=blue]
> "cjobes" <cjobes@nova-tech.org> wrote in news:OAvLiZa1EH A.324
> @TK2MSFTNGP10.p hx.gbl:
>[color=green]
> > Hi all,
> >
> > I have a date field in a temp table as part of a DataSet. In some[/color][/color]
records[color=blue][color=green]
> > the value is DBNull. how can I trap the error with
> > if dtTemp("When") = ??? Then.....[/color]
>
>
> If dtTemp("When") is system.dbnull.v alue then
> Msgbox("oops dbnull!")
> end if
>
>
>
> --
> Lucas Tam (REMOVEnntp@rog ers.com)
> Please delete "REMOVE" from the e-mail address when replying.
> http://members.ebay.com/aboutme/coolspot18/[/color]

[bblyth]

Re: How to trap DBNull?

You Need to Edit the ItemArray associated with that row.

Also Rows.Add does work in a round about way

Dim DT As New Data.DataTable
Dim DR As Data.DataRow
DR = DT.NewRow
DR.ItemArray(0) = "Test"
DR.ItemArray(1) = "Test2"
DT.Rows.Add(DR)


"cjobes" wrote:
[color=blue]
> Thanks, that worked.
>
> Now that the project doesn't time out anymore, I found another problem.
> Where the dtTemp("When") column is not DBNull I need to replace the value of
> another column (dtTemp("When2" ) with a value of a specific variable.
> Rows.Add doesn't work (although the books say that if the PK value for the
> record is already there it would replace the data) and there isn't anything
> like "change" or "replace". How can I do this?
>
> Thanks,
>
> Claus
>
>
> "Lucas Tam" <REMOVEnntp@rog ers.com> wrote in message
> news:Xns95AFC39 7C92C5nntproger scom@140.99.99. 130...[color=green]
> > "cjobes" <cjobes@nova-tech.org> wrote in news:OAvLiZa1EH A.324
> > @TK2MSFTNGP10.p hx.gbl:
> >[color=darkred]
> > > Hi all,
> > >
> > > I have a date field in a temp table as part of a DataSet. In some[/color][/color]
> records[color=green][color=darkred]
> > > the value is DBNull. how can I trap the error with
> > > if dtTemp("When") = ??? Then.....[/color]
> >
> >
> > If dtTemp("When") is system.dbnull.v alue then
> > Msgbox("oops dbnull!")
> > end if
> >
> >
> >
> > --
> > Lucas Tam (REMOVEnntp@rog ers.com)
> > Please delete "REMOVE" from the e-mail address when replying.
> > http://members.ebay.com/aboutme/coolspot18/[/color]
>
>
>[/color]

[cjobes]

Re: How to trap DBNull?

When I try this I get an error msg that the row already belongs to the
table. I also to update the item by assigning the new value to
TableX.ItemArra y(3)="new value"
One column is configured as PK auto.

"bblyth" <bblyth@discuss ions.microsoft. com> wrote in message
news:8D34037B-F85C-425F-A810-DE666A9209AA@mi crosoft.com...[color=blue]
> You Need to Edit the ItemArray associated with that row.
>
> Also Rows.Add does work in a round about way
>
> Dim DT As New Data.DataTable
> Dim DR As Data.DataRow
> DR = DT.NewRow
> DR.ItemArray(0) = "Test"
> DR.ItemArray(1) = "Test2"
> DT.Rows.Add(DR)
>
>
> "cjobes" wrote:
>[color=green]
> > Thanks, that worked.
> >
> > Now that the project doesn't time out anymore, I found another problem.
> > Where the dtTemp("When") column is not DBNull I need to replace the[/color][/color]
value of[color=blue][color=green]
> > another column (dtTemp("When2" ) with a value of a specific variable.
> > Rows.Add doesn't work (although the books say that if the PK value for[/color][/color]
the[color=blue][color=green]
> > record is already there it would replace the data) and there isn't[/color][/color]
anything[color=blue][color=green]
> > like "change" or "replace". How can I do this?
> >
> > Thanks,
> >
> > Claus
> >
> >
> > "Lucas Tam" <REMOVEnntp@rog ers.com> wrote in message
> > news:Xns95AFC39 7C92C5nntproger scom@140.99.99. 130...[color=darkred]
> > > "cjobes" <cjobes@nova-tech.org> wrote in news:OAvLiZa1EH A.324
> > > @TK2MSFTNGP10.p hx.gbl:
> > >
> > > > Hi all,
> > > >
> > > > I have a date field in a temp table as part of a DataSet. In some[/color]
> > records[color=darkred]
> > > > the value is DBNull. how can I trap the error with
> > > > if dtTemp("When") = ??? Then.....
> > >
> > >
> > > If dtTemp("When") is system.dbnull.v alue then
> > > Msgbox("oops dbnull!")
> > > end if
> > >
> > >
> > >
> > > --
> > > Lucas Tam (REMOVEnntp@rog ers.com)
> > > Please delete "REMOVE" from the e-mail address when replying.
> > > http://members.ebay.com/aboutme/coolspot18/[/color]
> >
> >
> >[/color][/color]

[Cor Ligthert]

Re: How to trap DBNull?

Claus,

Why would you add a row when you have to change an item in a column.
To give some explanation about items and columns.

A column is the description of a datatable column in such a column are items
Therefore
\\\
dim mycolumname as string = mytable.columns (0).columnname
///
gives you the name of the column
\\\
dim mycolumnitem as string = mytable.rows(0) .item(0) or
dim mycolumnitem as string = mytable.rows(0) .item(mycolumnn ame)
///
Gives you the first item in the first row

Therefore you need probably something as
\\\
mytable.rows(0) .item(0) = myvalue
///
I hope this helps?

Cor

"cjobes" <cjobes@nova-tech.org> schreef in bericht
news:OZtXnCb1EH A.1124@tk2msftn gp13.phx.gbl...[color=blue]
> Thanks, that worked.
>
> Now that the project doesn't time out anymore, I found another problem.
> Where the dtTemp("When") column is not DBNull I need to replace the value
> of
> another column (dtTemp("When2" ) with a value of a specific variable.
> Rows.Add doesn't work (although the books say that if the PK value for the
> record is already there it would replace the data) and there isn't
> anything
> like "change" or "replace". How can I do this?
>
> Thanks,
>
> Claus
>
>
> "Lucas Tam" <REMOVEnntp@rog ers.com> wrote in message
> news:Xns95AFC39 7C92C5nntproger scom@140.99.99. 130...[color=green]
>> "cjobes" <cjobes@nova-tech.org> wrote in news:OAvLiZa1EH A.324
>> @TK2MSFTNGP10.p hx.gbl:
>>[color=darkred]
>> > Hi all,
>> >
>> > I have a date field in a temp table as part of a DataSet. In some[/color][/color]
> records[color=green][color=darkred]
>> > the value is DBNull. how can I trap the error with
>> > if dtTemp("When") = ??? Then.....[/color]
>>
>>
>> If dtTemp("When") is system.dbnull.v alue then
>> Msgbox("oops dbnull!")
>> end if
>>
>>
>>
>> --
>> Lucas Tam (REMOVEnntp@rog ers.com)
>> Please delete "REMOVE" from the e-mail address when replying.
>> http://members.ebay.com/aboutme/coolspot18/[/color]
>
>[/color]

[Ken Tucker [MVP]]

Re: How to trap DBNull?

Hi,

The datarow has an isnull method to tell if a field is dbnull.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemdatadatarowclassisnulltopic.asp

Ken
-----------------------
"cjobes" <cjobes@nova-tech.org> wrote in message
news:OAvLiZa1EH A.324@TK2MSFTNG P10.phx.gbl...
Hi all,

I have a date field in a temp table as part of a DataSet. In some records
the value is DBNull. how can I trap the error with
if dtTemp("When") = ??? Then.....

Thanks,

Claus