Number of rows returned from ObjectDataSourc e.FilterExpress ion

[John]

How can I find how many rows are returned from the DataView generated by
FilterExpressio n on an ObjectDataSourc e?

I can get the number of rows in the underlying datatable by using:

protected void mydataSource_Se lected(object sender,
ObjectDataSourc eStatusEventArg s e)
{
numrows = ((DataTable) e.ReturnValue). Rows.Count;
}

But I can't get access to the dataview used by FilterExpressio n. It's not
((DataTable) e.ReturnValue). DefaultView

Thanks,

John

[Manu]

e.ReturnValue should be of type DataView

[John]

I double checked, e.ReturnValue is a strongly typed datatable, not a
dataview.

I found that calling objDataSource.S elect() returns a dataview with the
filter applied, *but* this seems to result in a double call with the built
in databinding - unless you turn caching on.

Any ideas how to avoid the double call?

John

"Manu" <ma******@gmail .com> wrote in message
news:11******** *************@p 10g2000cwp.goog legroups.com...

e.ReturnValue should be of type DataView

[John]

This seems to work, but it's a bit clunky:

If the only way to get the dataview is to call objDataSource.S elect(), we
need to prevent the automatic databinding, otherwise a second SQL call will
result. I did the following in Page_PreRender:

DataView dv = myDataSource.Se lect() as DataView;
myDataSource.Da taSourceID = null; // break the auto-binding
amyDataSource.D ataSource = dv; // allow it to respond to manual
binding
DataBind();

This results in only one call to the SQL, and a dataview you can work with.

It would be so much better if this was made available in
ObjectDataSourc e.Selected

John

"John" <jo**@nowhere.c om> wrote in message
news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..

I double checked, e.ReturnValue is a strongly typed datatable, not a
dataview.

I found that calling objDataSource.S elect() returns a dataview with the
filter applied, *but* this seems to result in a double call with the built
in databinding - unless you turn caching on.

Any ideas how to avoid the double call?

John

[John]

But changing the binding from GridView.DataSo urceID to DataSource seems to
break sorting.

Ho hum.

I'll have to go back to caching the result for a couple of seconds between
the two calls to ObjectDataSourc e.Select() (my manual call, then the
automatic databinding one).

There must be a better way!!!

John

"John" <jo**@nowhere.c om> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

This seems to work, but it's a bit clunky:

If the only way to get the dataview is to call objDataSource.S elect(), we
need to prevent the automatic databinding, otherwise a second SQL call
will result. I did the following in Page_PreRender:

DataView dv = myDataSource.Se lect() as DataView;
myDataSource.Da taSourceID = null; // break the auto-binding
myDataSource.Da taSource = dv; // allow it to respond to binding
without calling Select() again