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Q148332: BUG: GRID: SET RELATION TO Does Not Break Relation Properly

Article: Q148332
Product(s): Microsoft FoxPro
Version(s): WINDOWS: 3.0,3.0b,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): kbvfp kbvfp300bBUG kbvfp500aBUG kbvfp500bugkbbuglist
Last Modified: 24-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0 
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SYMPTOMS
========

When you use the SET RELATION TO command to break an existing relationship, the
only records displayed from the relationship's child table are those that are
related to the current parent record and beyond. Any child records that match
parent records prior to the current parent record are left out.

WORKAROUND
==========

Method One
----------

After using the SET RELATION TO command to break the relation, use the SELECT
command to select the child table, and then use the USE command. This closes the
child table.

Open the table again by using the USE command. Set the RecordSource property of
the grid back to the child alias. The code to do this would look similar to this
code:

     SELECT orders              && Select the child table
     USE                        && Close the child table
     USE orders ORDER cust_id   && Open the child table and reset the order
     ThisForm.Grid1.RecordSource = "Orders"    && Reset RecordSource
     ThisForm.Refresh           && Refresh the form

Method Two
----------

Use the following code to break the relation. This will allow you to see all the
child records in the grid without resetting any of the grid properties.

  ThisForm.LockScreen = .T.  && Lock the form
     SELECT orders              && Select the child table
     nChildRec = RECNO()        && Store the current child record number
     SELECT customer            && Select the parent table
     nParentRec = RECNO()       && Store the current parent record number
     GO TOP                     && Go to the top record in the parent table
     Thisform.Refresh()
     SET RELATION TO            && Break the relation
     ThisForm.Grid1.RecordSource = ThisForm.Grid1.RecordSource
     * Force the grid to look at the child table again
     SELECT orders              && Select the child table
     GO nChildRec               && Go to the child record we were on
     SELECT customer            && Select the parent table
     Go nParentRec              && Go to the parent record we were on
     Thisform.Refresh()
     ThisForm.LockScreen = .F.  && Unlock the form


STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products listed at
the beginning of this article. We are researching this problem and will post new
information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION
================

Steps to Reproduce Problem
--------------------------

1. Create a new form, and on that form, place a text box, a grid, a vcr command
  group, and a command button to break the relation. (The vcr command group can
  be found in the Buttons.vcx file located in VFP\Samples\Classes.)

2. In the Load event of the form, add the following code:

     USE customer IN 0
     * Customers.dbf and Orders.dbf can be found in VFP\Samples\Data
     USE orders IN 0 ORDER cust_id
     SELECT CUSTOMER
     SET RELATION TO cust_id INTO orders

3. In the Init event of the form, add the following code:

     ThisForm.Text1.ControlSource = "cust_id"
     ThisForm.Grid1.RecordSource = "orders"
     ThisForm.Grid1.RecordSourceType = 1

4. Place the following code in the Click event for the Break command button:

     SELECT customer
     SET RELATION TO
     thisform.grid1.recordsource='orders'
     ThisForm.Refresh

5. In the Unload event of the form add the following code:

     select customer
     use
     select orders
     use

6. Open the View window, and run the form.

7. Make a note of the customer id number in the text box, and skip through the
  first three records.

8. Click the Break command button.

9. Notice that the relation no longer exists in the View window and the only
  records available in the grid are those that match the current parent record
  and beyond. No previous records are available.

Additional query words: kbvfp300 kbvfp500 kbvfp600

======================================================================
Keywords          : kbvfp kbvfp300bBUG kbvfp500aBUG kbvfp500bug kbbuglist
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b kbVFP500 kbVFP600 kbVFP500a
Version           : WINDOWS: 3.0,3.0b,5.0,5.0a,6.0
Issue type        : kbbug

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