Master/Detail with JIT

rbuser

Hi,

I've checked the master/detail demo - however, I cannot find
out how to use/create a decent master/detail report with the
JIT pipelines that need to traverse over multiple object structures.

That is, how and when do I control what is the current master
record and how many detail records the subreport has?

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With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions
http://www.upscene.com

nicocizik

Hi Martijn,

You were a bit unclear about which demo you had taken a look at. Have you
seen Demo 139? This demo shows how to create a master-detail style report
using JITPipelines. I am also unclear about how you want to control which
Master is the current one. ReportBuilder will traverse all Masters and all
Detail fields pertaining to it based on how the master and detail pipelines
are linked.

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rbuser

Hi Nico,


I'm sorry - it was already quite late when I wrote that.


Yes, 139 ... but...


On each "next row" of the master, I need to select a different (detail) source
and
recordcount my detail rows. I cannot find this in Demo 0139 - if it is in there,
please explain where and how.

I need to set a new recordcount for the detail rows after the master pipeline
goes to the next record.

Any ideas?


--

With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions
http://www.upscene.com

nicocizik

Hi Martijn,

The reason demo 139 works is that the datapipelines are linked so when the
master record changes, the detail records change automatically. This then
requires no need to change the detail source or record count. If you would
still need to do this manually, check out the OnMasterRecordChange event and
use that to change your detail information.

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rbuser

Nico,


But from what I understand from Demo 0139, is that all the detail data is
available at report startup, and filtered/positioned during reporting, right?


In my case, the amount of detail data is available whenever the master row
changes, but I cannot figure out how?


--

With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions
http://www.upscene.com

nicocizik

Hi Martijn,

From what I understand, you need to change the detail datasource depending
on which master you are currently accessing. This is not how a
Master-Detail relationship is defined in the Report Engine. Your best bet
as I mentioned before is to try to use the OnMasterRecordChange and try to
feed the Report the correct data every time the master record changes.
Another alternative you may want to explore is using an in-memory dataset
such as kbmMW (www.components4developers.com), rather than a JIT Pipeline.

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rbuser

Hi Nico,


Not really the datasource, but only its data.


What does ReportBuilder expect? One large chunk of detail data that gets
filtered by a master value?

Can I "open" and "close" a detail in order to get a different detail
recordcount?


If RB expects one large chunk of detail data, doesn't it fetch way too much
data from real datasets? Or is a master WHERE clause applied to the detail
as well? (just asking)


--

With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions
http://www.upscene.com

nicocizik

Hi Martijn,

ReportBuilder will traverse the entire Master and Detail datasets unless
they are filtered in any way either using an SQL query or Delphi Table
Filtering. The only way the Report Engine knows which Detail records apply
to a given Master record is through the datapipeline or table linking done
before the engine starts. I am still a bit unclear about the results you
are trying to get. Do you want to limit the number Detail records that the
Report Engine traverses or do you want to filter out certain records for
each Master record? If the datasets are linked, the Master 'where' clause
will not affect the number of Detail records per Master record, but it will
affect the number of Detail records total.

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rbuser

Hi Nico,


Right - I stopped using Master/Detail - it doesn't make sense for what
I'm trying to do...

Thanks for the explanation - once I figured this out, it was pretty easy
to solve my problems.


--

With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions
http://www.upscene.com

nicocizik

Glad to help .

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