Hi,

I'm working with a filtered dataset in EDB 2.04B4 and have come across an issue where (at first) Locate appeared to fail for no apparent reason. Some simplified code below:

ds->Filtered = true;
ds->OnFilterRecord = MyOnFilterRecord;

void __fastcall TMyForm::MyOnFilterRecord(TDataSet *DataSet, bool &Accept)
{
     Accept = DataSet->FieldByName("Type")->AsInteger != 16;
}

This is the recordset
ProductCode         Type
320802                  8
320802                  8
320802                  16
293709                  8


Calling  ds->Locate("ProductCode", 320802) returns False each time in this case. If filter is removed, Locate works again.

I figured out that Locate happens to find the third record (with Type = 16) and filters it out. It then moves to the next record (with ProductCode = 293709), which does not match the original criteria, so it returns False.

Is there any workaround for this?

Instead of moving to the next record after OnFilterRecord rejects the current record, could Elevate try to recursively call Locate again, this time excluding the record that was filtered out in the first round?

Chris


I'm a Delphi user so maybe there's a good reason for your using the OnFilter event. If not and your filter condition is as simple as it seems why not just try a simple filter eg in Delphi

table.Filter := 'Type <> 16';
table.Filtered := True;

Roy Lambert [Team Elevate]

Roy Lambert wrote:
<< I'm a Delphi user so maybe there's a good reason for your using the OnFilter event. If not and your filter condition is as simple as it seems why not just try a simple filter eg in Delphi

table.Filter := 'Type <> 16';
table.Filtered := True; > >

Hi Roy,
The example I've given is very simplistic and only there to demonstrate the problem. Our production code is much more complex. A Filter is actually used for some of the simple conditions. OnFilter event is used on top of the Filter.

Cheers,
Chris

Chris

>The example I've given is very simplistic and only there to demonstrate the problem. Our production code is much more complex. A Filter is actually used for some of the simple conditions. OnFilter event is used on top of the Filter.

In that case what about moving from a table to a query? It might mean an insensitive result set which could be a problem.

Roy Lambert [Team Elevate]

Is a official bug ?

I'm using 2.03 Build 14 but... i'm working now for move to Delphi XE and EDB
2.4 Build 4

if there is this bug i'm wait .. Build 5 ^^

Roy Lambert wrote:
In that case what about moving from a table to a query? It might mean an insensitive result set which could be a problem.


Roy,
I'm not sure what you're getting at. The resultset is already insensitive in this case.
How would the change fix problems with Locate?

Chris

>In that case what about moving from a table to a query? It might mean an insensitive result set which could be a problem.

>I'm not sure what you're getting at. The resultset is already insensitive in this case.
>How would the change fix problems with Locate?

I was assuming you were using a table not a query. I'm now guessing that since the resultset is insensitive that you're using a query. In which case, since you're already working with an insensitive query can you not build the filter and onfilter stuff into the sql producing the resultset? Locate should then work as expected.

Roy Lambert [Team Elevate]

Chris,

<< Is there any workaround for this? >>

The issue is caused by doing a Locate on a non-indexed column.  The only
workaround is to make sure that the column that you're searching on is
indexed.  A fix will be in the next release.

--
Tim Young
Elevate Software
www.elevatesoft.com