> DataRow r = DataTable.Rows[0];
>
> and the row has a column named FirstName, can I do this:
>
> r["FirstName"] = "Rod";
>
> or do I have to do something like this first:
>
> r.BeginEdit();
> r["FirstName"] = "Rod";
>
> And if I do have to use the BeginEdit() method, do I also have to issue
> the EndEdit() method? Or will that basically clear the row's Current view
> and reassign that to the Original view?
If you are doing this programatically, then no you don't. THe problme is
that when you use the UI, often it will start the beginedit but nothing
triggers the end edit. HOwever, I'd highly recommed that you do use
beginedit. If you don't, then for instance, if your values are sorted, it
could affect the sort immediately.
>
> I know that the datarow's SourceVersion will come into play, but I am not
> sure how.
>
> Second question: What DOES the Update() method of the SqlDataAdapter
> really work on? For example, after struggling with this for half the day
> I finally got rid of the error message I was getting saying,
>
> "Procedure 'spMyProc' expects parameter '@FirstName', which was not
> supplied"
>
> to go away, but now when I assign a value to the datarow's FirstName
> column, then I would have expected that to actually be saved to the
> database when I issued the SqlDataAdapter's Update() method. Instead, it
> just quietly goes about its business and nothing at all is saved/updated.
> So, what I am doing wrong now?
>
> Rod
Update goes through each row and looks at the RowState. If it's modified,
added, deleted, then it looks to the corresponding command and fires it. If
you look at the overload for a dataColumn DataColumn dc = new
DataColumn("ColumnName", typeof(Whatever), Column). This is the value that
will map back to the parameter if you've coded your CRUD correctly or of you
had it generated. IF you don't have any changeds, you can call Update all
year and nothing will happen. If you call Update and you have modified rows
but no update command, you'll get an exception. It maps those values back to
the params.
Does this answer your question?
BTW< I'd highly encourage using a Keyed table, and using the DataAdapter
Configuration wizard and deconstructing what it created. You'll learn a
lot - or at least, I did.
--
W.G. Ryan, MVP
www.tibasolutions.com |
www.devbuzz.com |
www.knowdotnet.com
"Rod" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>I have been using .NET for three years. We are currently using VS .NET
>2003 and SQL Server 2000. Whenever I have needed to update data I normally
>created a SqlCommand object, assigned it the appropriate string (depending
>upon whether it is a stored procedure or not) and executed it. However,
>now I would like to use the SqlDataAdapter's UpdateCommand and Update()
>method.
>
> However, I am running into problems, which I think I can break down into
> two questions. The first is, how do I assign values to the dataset which
> I want to be updated? For example, if I have something like this:
>
>
> I know that the datarow's SourceVersion will come into play, but I am not
> sure how.
>
> Second question: What DOES the Update() method of the SqlDataAdapter
> really work on? For example, after struggling with this for half the day
> I finally got rid of the error message I was getting saying,
>
> "Procedure 'spMyProc' expects parameter '@FirstName', which was not
> supplied"
>
> to go away, but now when I assign a value to the datarow's FirstName
> column, then I would have expected that to actually be saved to the
> database when I issued the SqlDataAdapter's Update() method. Instead, it
> just quietly goes about its business and nothing at all is saved/updated.
> So, what I am doing wrong now?
>
> Rod
>
>
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