Updating dataview calc field unhooks any dbText fields

rbuser

RB7.04 D6 Dade EUR SQL Server

Step 1) create a calc column of say Left(cut.name, 5) and then use it
in a dbText field
Step 2) modify field to be Left(cut.name, 10)

This unhooks the dbText field and you have to manually find it and
re-assign the field. Even if you had renamed the calc field it is
unhooked. Because the SQL alias changes?

Is this intentional? Can it be changed? How could I go about
changing it?

Thanks,
Rick Matthews
Dartek Systems Inc.

nardmoseley

I don't know of any way around that. The underlying field name (the SQL
alias) is changing and that is causing different fieldnames to be created.
The FieldAlias displayed in the designer always maps to the fieldname and
the DBText.DataField contains the fieldname value.

You can check out TdaQueryDataView.CreateField located in
daQueryDataView.pas to see where the fields get created.

--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com

rbuser

Nard,

I see the problem. As a compromise, if the user sets the Alias (which
doesn't then change) of the calc field can I use it to hook back up
the components that referred to the now renamed SQL alias?

In TdaQueryDataView.SQLToDataView is it reasonable / safe to ripple
through the report looking for unhooked field components and hooking
them back up if I can find the FieldAlias? If so I think I need the
DataPipeline calcfields from before the updated dataview. Is there an
easy way to copy a pipeline?

Any hints or code snippets would be greatly appreciated.

Thanks,

nardmoseley

You can try doing that. I do not know how safe it is, I cannot think of any
issues off the top of my head. To copy the pipeline fields, try creating a
pipeline and then loop thru the original pipeline fields and change the
DataPipeline (i.e. parent).

mySavePipeline := TppDBPipeline.Create(myPipeline.Owner);

for liIndex := myPipeline.FieldCount-1 downto 0 do
myPipeline.Fields[liIndex].DataPipeline := mySavePipeline;



--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com

rbuser

Thanks Nard that was just what I was looking for. No guarantees of
safety I know.

Cheers,