Updating comboboxs and lookup tables

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

I have created many forms from 3 tables. I am looking for a simple way to be
able to update forms when I make changes to the underlying tables. I make
additions to the value list for a combobox in the underlying table but can
not get it to update on the forms. I fear this for the lookup tables I also
have that I need to update periodically.
 
Do not use a value list as the RowSource for a combo box other than with
fixed value lists like days of the week, months of the year etc. By using a
value list which you need to update from time to time you are storing data in
the list. Data must only be stored as values in tables. This is a
fundamental principle of the relational database model, known as the
Information Principle and expressed formally as follows:

'The entire information content of the database is represented in one and
only one way, namely as explicit values in column positions in rows in
tables'.

If data is stored only in tables then any combo or list box controls on
forms will reflect any changes you make to the data in the look-up tables.
If the data is changed while a form with a list or combo box which uses that
data for its RowSource then the control will need to be requeried to reflect
the changes while the form is open.

When you have related 'look-up' tables like this you should also ensure that
referential integrity is enforced in the relationships.

Ken Sheridan
Stafford, England
 
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