DataView.Find

14 Jan 2005 9:01 PM

michael

It seems that the DataView.Find differs from the DataRowCollection.Find
method. The latter searches the Primary Key of the table for the object
supplied as the "key" parameter. However, where the DataView.Find is
concerned, it seems that the Primary Key of the table is not the column
searched, rather, it is the column specified in the DataView.Sort member. So
far so good.

But, what happens with the DataView.Find(key()) flavor of this method. I
assume that it will again search the DataView.Sort member column, but what
happens when the Key is an array with more than one element? If I use dim
key(1) as Object, and then assign each element a value, does that mean that
the DataView.Sort member must be made up of 2 columns, seperated by a comma?

Michael

PS. I also noticed that the method return's -1 and not null when a row isn't
found.

--
Michael Hockstein

15 Jan 2005 7:00 AM

Kevin Yu [MSFT]

Hi Michael,

First of all, I would like to confirm my understanding of your issue. From
your description, I understand that there is some misleading in the MSDN
documentation for DataView.Find method. If there is any misunderstanding,
please feel free to let me know.

Actually, DataView.Find accept values for the columns on which DataView is
actually sorted which is not always primary key columns. The overload for
DataView.Find(object[]) is used when multiple columns are used as sort
columns. The example in the MSDN document won't work. Here, I'm posting a
correct example:

    DataView dv = new DataView(dt);
    dv.Sort = "FirstName, LastName";
    this.dataGrid1.DataSource = dv;
    object[] s = {"Nancy", "Davolio"};
    int i = dv.Find(s);

We have noticed this issue, and you can check it from the following link:

http://lab.msdn.microsoft.com/ProductFeedback/viewFeedback.aspx?feedbackid=4
c26fdcd-1e3d-48a9-96b3-ef0b066b5861

This will be fixed soon. HTH.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

15 Jan 2005 1:17 PM

michael

Maybe the documentation will be better in 2005.

Which method do you think would be faster, all other things equal(# of rows,
# of columns in key), the method in the DataRowCollection or the Dataview?

Michael

Show quote

"Kevin Yu [MSFT]" wrote:

> Hi Michael,
>
> First of all, I would like to confirm my understanding of your issue. From
> your description, I understand that there is some misleading in the MSDN
> documentation for DataView.Find method. If there is any misunderstanding,
> please feel free to let me know.
>
> Actually, DataView.Find accept values for the columns on which DataView is
> actually sorted which is not always primary key columns. The overload for
> DataView.Find(object[]) is used when multiple columns are used as sort
> columns. The example in the MSDN document won't work. Here, I'm posting a
> correct example:
>
>     DataView dv = new DataView(dt);
>     dv.Sort = "FirstName, LastName";
>     this.dataGrid1.DataSource = dv;
>     object[] s = {"Nancy", "Davolio"};
>     int i = dv.Find(s);
>
> We have noticed this issue, and you can check it from the following link:
>
> http://lab.msdn.microsoft.com/ProductFeedback/viewFeedback.aspx?feedbackid=4
> c26fdcd-1e3d-48a9-96b3-ef0b066b5861
>
> This will be fixed soon. HTH.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."
>
>

18 Jan 2005 6:55 AM

Kevin Yu [MSFT]

Hi Michael,

The two methods, DataRowCollection.Find and DataView.Find, find data in
different kind of columns. DataRowCollection.find must find in a column
that is the primary key in a DataTable, while DataView.Find must find in a
sorted column.

If the primary key column is also the sorted column, I think DataView.Find
will be faster, since it looks for rows in a sorted column.

HTH.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."