Indicate different statistic values (max value, min value, mean value etc) for one fi

[Madda91]

Hello everyone!
I´m quite new with Access and I´m not able to understand if what I have in mind can be done with Access or not.
Let me explain: my aim is to create a database of landslides where each landslide is described by different parameters. So in the table of "LANDSLIDE 1" I´ll have all the information about this landslide (location, length, width, altitude, etc). For some parameters I need to indicate different values e.g. for the altitude field I want to indicate the maximum altitude, the mininum altitude, the mean altitude, etc.
Is there a way to create these sub-fields (max, min, mean, etc) within one main field (e.g. altitude)?
Thanks a lot!

[twinnyfo]

Madda91,

Welcome to Bytes!

What you are talkilng about has to do with what us database guys call "Normalization". That's just a big word for "designing a database with a proper structure." There is a Bytes Article on Normalization that can help you through some of the theoretical aspects of DB normalization.

To more directly answer your question, conceptually, I would have a table called tblLandslides, which gives general information about each particular event (since multiple landslide could occur at the same location, we treat each event as a single entity). The Location of the landslide would be one of your fields.

Then, I would have atable called tblLocations, which lists those details about the altitude, etc. for each location at which a Landslide occurs. I would have separate fields for Min/Max/Mean.

All this just depends upon how detailed your reports on landslides need to be.

Although we can't build such a monster for you, we can help you work through whatever details you needs to manage.

Hope this hepps!

[PhilOfWalton]

What you want looks very easy to accomplish, but you need to do a little reading about database normalisation.

You must bear in mind that a table should contain only raw data, it should NOT contain calculated fields. Those calculations are usually done using Queries, and the results seen on forms or reports.

So, assuming your mean altitude is the average of max & min altitude, those are the two values to store in your table.

Phil

[Madda91]

Thank you very much for your reply! It really helps

The idea of creating different tables for multi values parameters occurred to me, but I was worried about the large number of tables I´d come up with. But now I understood that Access is all about tables and queries between tables so I will do it this way.

Thanks again!

[Madda91]

Thank you Phil for the specification! I would have done it wrong without it.

Madda

[NeoPa]

PhilOfWalton:
So, assuming your mean altitude is the average of max & min altitude, those are the two values to store in your table.

That may be the case with either - only two values or - a perfectly even spread of data. Otherwise that won't be an assumption you'll want to make.