i think you're not quite getting the idea of normalization and "supporting"
(lookup) tables. one issue in normalization is that you don't put multiple
instances of a value in different fields in the same record. for instance,
if you need to connect a salesman to several cities that he covers, you
don't put multiple city fields in the same table, as City1, City2, City3,
City4, etc. instead, you would put the cities in a child table. the salesman
table would have a one-to-many relationship with salescities table. one
salesman record can be related to many salescity records BUT each salescity
record is only related to one salesman. that's one step in the normalization
process.
supporting tables are a different issue, not really related to
normalization. you generally use a supporting table to list data that you're
going to use to populate a droplist. this makes it easy to 1) control and
limit the data that may be entered in a field and 2) ensure that the display
values are correctly spelled, capitalized, etc.
to solve your addresses issue: create a separate table for cities, as
tblCities
CityID (primary key - data type as AutoNumber)
CityName
enter all the city names you need - or think you may need - for your various
addresses.
in your addresses table, set the data type for the City field as Long
Integer. that matches the autonumber data type for the primary key field of
tblCities. set a one-to-many relationship between CityID (one) in tblCities
and City (many) in tblAddresses.
in your Address data entry form, use a combo box to enter the City name.
base the combo box on tblCities. read up on combo boxes in Help for details.
also, you can use the Control Wizard in form design view to build the combo
box for you - makes it very easy.
hth
"PF" <(E-Mail Removed)> wrote in message
news:dxyKc.376$(E-Mail Removed)...
> Tanks for your answers.
>
> For question 1
>
> In tblcustomer, each customer has a buyer associated with it.
> instead of repeating the name of the buyer in each row, i want to put the
> buyer name
> in a separate table with a link field.
>
> If i do that i will have to modified the program use to retrieve
information
> from the tables.
>
> I am wondering if it worth it. Will i save lookup time enough to justify
the
> modification.
>
> Suppose you have a customer table with address and a separate field for
> city.
> Is it a common practice to normalize that field? i.e. make a separate
table
> for city? It seems to me that it will bring complexity.
>
> For question 2
> does the wuh? mean -"Wake up everyone is using it" If i make a search on
> normalisation on this newsgroup the term is not appearing at all - i was
> surprise
>
>
> Question 3
> If i understand correctly i will have to import the ascii file in a
> temporary table
> and then rebuild each table in a normalise way, i.e. build a table with
> unique buyer name and unique id and then link it with the main table
etc...
>
> pierre
>
> "Tim Ferguson" <(E-Mail Removed)> a écrit dans le message de
> news:Xns9529D4D773457garbleme4455656@207.46.248.16...
> > "PF" <(E-Mail Removed)> wrote in
> > news:Ve9Kc.14123$(E-Mail Removed):
> >
> > >
> > > 1. tblcustomer with address and all data
> > > 2. tblBuyer a list of 5 names
> > > 3. tblType a list of number
> >
> > You have not given much of a clue about what these entities are, but I
am
> > not getting a good feeling about this design... <g>
> >
> > > Question 1
> > > What is the common use technique to add record?
> >
> > Just go to the "new" record on the form.
> >
> > > Lets say the user add a customer, he enter a new customer number and
> > > data, but when he will arrive a the buyer field what is the common way
> > > to handle that on a form
> >
> > Depends: you could use a combo box on the form with the RowSource
getting
> > information from the Buyers table. Or a commmand button could launch a
> > dialog (another form) that would carry out a search of the Buyers table.
> Or
> > you could have a textbox where you enter the buyer's name, and then have
> > some code look it up and return the ID number.
> >
> > > Question 2
> > > How come there are no question on normalisation in table design forum?
> > > Is someone using that?
> >
> > Huh? -- practically all of the questions that get answered here are
about
> > relational theory and good schema design. Normalisation is one method to
> > get there.
> >
> > > Question 3
> > > When i import from text file i would like to see an example of text
> > > transfer involving data normalised with vb.
> >
> > Not sure what you mean. "Data" are not "normalised", a design is. As for
> > text file import, there are many many ways to do it, depending on the
> shape
> > and cleanliness of the original data. Need more details.
> >
> > B Wishes
> >
> >
> > Tim F
> >
>
>
|