Microsoft Access

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How do i write an mathematical equation in database table design view?
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You don't.

Storing derived data such as this in your table accomplishes
three things: it wastes disk space; it wastes time (almost
any calculation will be MUCH faster than a disk fetch); and
most importantly, it risks data corruption. If one of the
underlying fields is subsequently edited, you will have data
in your table WHICH IS WRONG, and no automatic way to detect
that fact.

Just redo the calculation whenever you need it, either as a
calculated field in a Query or just as you're now doing it -
in the control source of a Form or a Report textbox.

John W. Vinson[MVP]
 
The short answer is, you don't!

Tables are for storing data. Equations are not data. Equations can produce
*calculated* data, but this should not be stored in a table. If you need
it, generate it in a query, and then use it on your form or report. Or
generate it directly in a calculated field in your form/report.

A very simple example:

Assume your table has two fields, Length and Height, and you want to
calculate Area, and display all three. In your query, insert the Length and
Height fields into the first two query fields; in the third field, type
Area: [Length] * [Height]

Run your query. Your output will be:

Length Height Area
4 2 8
3 3 9
1.5 3 4.5
....

HTH,

Rob
 
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