Home Datapipelines

MasterPipeLine problems

edited September 2004 in Datapipelines
Hi, I'm changing a Master/Detail Report from Delphi Query Linking to the
DataPipeline Linking .
For some reason this is just not working, but when I close the project and
open it again, the MasterPipeline property of all my pipelines is deleted.
I just select the Masterpipeline - save - close
the project - open the project... and the property is blanck again!!.

I dont know what is happening, I already change another report (on another
project) before and have not problems at all.

Someone knows what could it be?
Thanks a lot.
Eugenio Puente




++++++++++++++++++++++++++++++++++++++++++++++++++++++++



------------------------------------------------------
Tech Tip: Linking SQL Queries for Master/Detail Data
------------------------------------------------------

The following example shows two options for linking SQL queries to create a
master/detail relationship.

In this example, we are using Delphi's DBDemos data to create a
Customer/Order relationship. Thus we wish to link the Orders detail to the
Customer master.

I. Delphi Query Linking
------------------------

a. Set the detail TQuery.DataSource property to point to the master
query's TDataSource component.

b. In the SQL "Where" clause for the detail query use a ':' followed by
the linking field name from the master:

example
select *
from orders
where orders.CustNo = :CustNo

Now each time the master record position changes, the detail query will
automatically be refreshed with the correct result set.


II. RB DataPipeline Linking
-----------------------------

a. Set the detail DataPipeline.MasterDataPipeline to point to the master
DataPipeline.

b. Use the detail DataPipeline.MasterFieldLinks property to define the
linking relationship

c. In the SQL for the detail, retrieve all records and sort them by the
linking master field:

select *
from Orders
order by CustNo


Notes:

1. Using RB DataPipeline, each query is executed only a single time - thus
performance is much faster.

2. RB Professional and Enterprise Editions include a visual Data environment
for creating SQL queries, defining linking relationships, and creating
Ask-At-Runtime parameters. Using the RB tools you could create the above
linked queries in about 10 seconds.

Comments

  • edited September 2004

    1. Check that the datapipelines are Owned by the form/datamodule upon which
    they reside. Also try placing them on the same form/datamodule upon which
    the report resides.

    2. Below is an article on datapipeline linking. It amy contain some useful
    tips for you.

    3. If you still have an issue, create a simple, minimal example and email in
    zip format to support@digital-metaphors.com and we can check it out here.
    Use only standard Delphi components and RB.


    ------------------------------------------------------
    Tech Tip: Linking SQL Queries for Master/Detail Data
    ------------------------------------------------------

    The following example shows two options for linking SQL queries to create a
    master/detail relationship.

    In this example, we are using Delphi's DBDemos data to create a
    Customer/Order relationship. Thus we wish to link the Orders detail to the
    Customer master.

    I. Delphi Query Linking
    ------------------------

    a. Set the detail TQuery.DataSource property to point to the master
    query's TDataSource component.

    b. In the SQL "Where" clause for the detail query use a ':' followed by
    the linking field name from the master:

    example
    select *
    from orders
    where orders.CustNo = :CustNo

    Now each time the master record position changes, the detail query will
    automatically be refreshed with the correct result set.


    II. RB DataPipeline Linking
    -----------------------------

    a. Set the detail DataPipeline.MasterDataPipeline to point to the master
    DataPipeline.

    b. Use the detail DataPipeline.MasterFieldLinks property to define the
    linking relationship

    c. In the SQL for the detail, retrieve all records and sort them by the
    linking master field:

    select *
    from Orders
    order by CustNo


    Notes:

    1. Using RB DataPipeline, each query is executed only a single time - thus
    performance is much faster.

    2. RB Professional and Enterprise Editions include a visual Data environment
    for creating SQL queries, defining linking relationships, and creating
    Ask-At-Runtime parameters. Using the RB tools you could create the above
    linked queries in about 10 seconds.


    --
    Tech Support mailto:support@digital-metaphors.com
    Digital Metaphors http://www.digital-metaphors.com




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



    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
This discussion has been closed.