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Groups > comp.databases.ms-access > #9143

Re: Managing changes to combo box contents when values are contained in a table

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BobAlston <bobalston9@yahoo.com> wrote in
news:5320D8A3.90903@yahoo.com: 

> On 3/12/2014 12:44 PM, Ron Paii wrote:
>> Use a query instead of a table as the combo box's source.
>>
>> "BobAlston" <bobalston9@yahoo.com> wrote in message
>> news:lfq2ka$mjk$1@dont-email.me...
>>> I am interested in hearing from some of you experienced
>>> developers on how you design your table driven combo boxes to
>>> accommodate user changes to the table over time.  Access
>>> defaults to storing the key but displaying the text value.  That
>>> is cool. 
>>>
>>> If a user subsequently decides to change the combo box list
>>> contents, they could delete records (in the table feeding the
>>> combo box) that they no longer need.  Of course this would
>>> affect the historical data using that combo box selection.  The
>>> "proper" way around this is to set the relation so that the
>>> entry could not be deleted if there are related records with its
>>> key.  Relational theory!! 
>>>
>>> You can handle this by setting an "unused" flag in the table, to
>>> allow the old, no longer needed value, to remain, but not show
>>> up in the combo box. Unfortunately, this would prevent the
>>> decode action from displaying the value.  How do you handle
>>> that? 
>>>
>>> One way of handling that I have used is to have the unused
>>> indicator and sort the combo records so the unused are at the
>>> bottom of the list with "NOT CURRENTLY USED" in the display as
>>> column 2.  That makes the decode work.  And I add logic to
>>> produce an error if a user tries to select a Not Currently used
>>> value for an empty combo box field. 
>>>
>>> Of course, smart users can get around all this by simply typing
>>> the new 10 values of the combo box, over the existing 10 values,
>>> thereby destroying the historical data.
>>>
>>> I am interested in hearing from experienced developers about how
>>> they handle this?
>>>
>>> bob
>>
> If the query excludes records that are no longer used, then the
> text will no longer be displayed for old records having the no
> longer used value from that combo box.
> 
> Bob
> 
The query needs a Where Chause.If you are adding a new record, then 
filter only hte current values. If displaying existing records use 
the full list.

-- 
Bob Q.
PA is y I've altered my address.

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Thread

Managing changes to combo box contents when values are contained in a table BobAlston <bobalston9@yahoo.com> - 2014-03-12 11:39 -0500
  Re: Managing changes to combo box contents when values are contained in a table "Ron Paii" <None@none.com> - 2014-03-12 12:44 -0500
    Re: Managing changes to combo box contents when values are contained in a table BobAlston <bobalston9@yahoo.com> - 2014-03-12 16:58 -0500
      Re: Managing changes to combo box contents when values are contained in a table Bob Quintal <rquintal@sPAmpatico.ca> - 2014-03-13 10:24 +0000
  Re: Managing changes to combo box contents when values are contained in a table Neil <xxx@gmail.com> - 2014-03-12 16:16 -0500
  Re: Managing changes to combo box contents when values are contained in a table Hagen Weidlich <durragon@web.de> - 2014-03-14 22:14 +0100
    Re: Managing changes to combo box contents when values are contained in a table BobAlston <bobalston9@yahoo.com> - 2014-03-14 21:05 -0500
      Re: Managing changes to combo box contents when values are contained in a table "Phil" <phil@stantonfamily.co.uk> - 2014-03-15 09:55 +0000
      Re: Managing changes to combo box contents when values are contained in a table Hagen Weidlich <durragon@web.de> - 2014-03-15 17:14 +0100

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