MasterFieldLinks at runtime

rbuser

Is it possible to set the MasterFieldLinks property of a TppDBPipeline at
runtime?
If so how is it done?
MyPipe.MasterFieldLinks := MyMasterField=MyChildField; ?

or what other way

Bill

digitalmetaphors

Please see the information below as well as the following demo.

http://www.digital-metaphors.com/tips/MagicMasterDetail.zip

---------------------------------------------------------
Tech Tip: Define Master/Detail DataPipeline Links in Code
---------------------------------------------------------

Defining a Master/Detail relationship for a DataPipeline
requires that the detail pipeline have the
following properties defined:

1. MasterDataPipeline

2. MasterFieldLinks


At Delphi design-time you can use the object inspector
and the DataPipeline's FieldLinks editor to define
the master/detail relationship.


The following example illustrates how to define the
master/detail relationship dynamically at run-time.


var
lFieldLink: TppMasterFieldLink;


begin

{define the master/detail pipeline relationship}
plDetail.MasterDataPipeline := plMaster;

{create a new field link }
lFieldLink := TppMasterFieldLink.Create(nil);

lFieldLink.Parent := plDetail;

{assign the detail field name}
lFieldLink.DetailFieldName := 'CustNo';

{assign the master field name}
lFieldLink.MasterFieldName := 'CustNo';


end;


Note: The DataPipeline linking requires the records in the detail dataset to
be ordered by the linking fields. In the above example, the detail data must
be ordered by CustNo.


--
Cheers,

Alexander Kramnik
Digital Metaphors

rbuser

Alexander,
Thank you for the response. However I have come up with the following
workaround.
For the subreport that will be showing all of the child records I did the
following.
In the Detail of the SubReport I put the following on the BeforePrint event.

Detail.Visible := ChildPipeline['LinkField'] = MasterPipeline['LinkField'];

It works pretty fast and I don't need to order them (even though I do).

This way it only opens the master and child query once and the results are
the same.

Bill


"Alexander Kramnik (Digital Metaphors)" wrote