Re: Microsoft Access, Double Data Entry and breaking the Normalization rule

On May 29, 8:42 pm, "David W. Fenton" <XXXuse...@xxxxxxxxxxxxxxxxxxx>
wrote:
"Tony Toews [MVP]" <tto...@xxxxxxxxxxxxxxx> wrote innews:up2p53p5kd7dlnuckscti79klvaula90ki@xxxxxxx:

"hippome...@xxxxxxxxxxxxxx" <hippome...@xxxxxxxxxxxxxx> wrote:

On the other hand, it seems that it might be easier to
"de-Normalize"
the table slightly to have a [DtaRspn1] and a [DtaRspn2] field.

This is not denormalizing. You have the same data but entered
twice. It's perfectly legitimate to do this.

At the concept or overview lefel this is similar to storing the
cost and price of an item when you sell the item. After all the
cost and price could change moments after the transaction is
entered.

Yes, but there are different ways to store the data:

1. double the fields in a single record.

2. have two records in a single table, with identical structure.

3. have two separate tables with identical structure.

4. have a main table and then a narrow side table that records only
the discrepancies, one field per record.

The worst of all seems to me to be the 1st choice, which is, I
believe, what the OP is considering.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

Thanks David. Unfortunately, I have to store the 2nd entry so the
unbound form method would not work.

Currently the db is set-up with option 2 (two records in same table).
This works very well for validation purposes, when the validation is
done after the entry. The VBA code that I developed easily compares
Entry 1 to Entry 2 and generates an output. However, for instantaneous
validation, it does not work as well. This is the main reason I'm
considering switching to option 1. I think it would allow for an
easier and more instantaneous comparison of entry 2 to entry 1. It
should actually only add 2 fields to each record (one for the
response, and one to record the time of entry).

Why do you think that this option is the worst? The only potential
disadvantage that I can foresee is that if a "record" is deleted
accidentally, it would be easy to miss. However, the database is well
secured from the end-users, and I have queries that check against
missing records prior to exporting to SPSS (since every participant is
supposed to have the same number of questions).

Your further thoughts would be appreciated.

Thanks,
Paul

PS. I've used two tables in the past, but found that having one table
generally worked better (validations were faster, querying easier,
etc).

.

Relevant Pages

  • Data Validation Problem Work-Around needed
    ... If the result of adding the two numbers created a duplicate in column ... once the data involved in a specific entry has been ... Data validation would work perfectly for this problem if it could be ... But the programming to do this by brute force would be ...
    (microsoft.public.excel.misc)
  • Re: Data Validation Problem Work-Around needed
    ... If the result of adding the two numbers created a duplicate in column ... once the data involved in a specific entry has been ... Data validation would work perfectly for this problem if it could be ... But the programming to do this by brute force would be ...
    (microsoft.public.excel.misc)
  • Re: Validation and tablelist trouble
    ... I don't understand the use of validation with interactive cell editing in tablelists. ... Trouble arises when entry's validatecommand edits the content of the entry widget. ...
    (comp.lang.tcl)
  • RE: Can anyone povide step by step instructions on how to do the f
    ... Exit Sub ' can't match on no entry ... We then use the Cells() property of a worksheet to use those values from ... validated lists down to start below row 1. ... If Excel's Help on topics such as Data Validation, ...
    (microsoft.public.excel.misc)
  • RE: Can anyone povide step by step instructions on how to do the f
    ... Exit Sub ' can't match on no entry ... We then use the Cells() property of a worksheet to use those values from ... validated lists down to start below row 1. ... If Excel's Help on topics such as Data Validation, ...
    (microsoft.public.excel.misc)