Column

[Nick Read]

Hi all

I want to create a column in a table (with no input
facility) where value in the column is equal to the sum of
the two previous columns, can you let me know how I can do
this,

Cheers


Nick

 

[Duane Hookom]

Is there a good reason for storing a value that can always be calculated in
a control source or in a calculated column in a query? You can write a query
like:
SELECT FieldA, FieldB, FieldA+FieldB As FieldC
FROM tblYourTable;

 

[John Vinson]

Hi all

I want to create a column in a table (with no input
facility) where value in the column is equal to the sum of
the two previous columns, can you let me know how I can do
this,

Well, as Duane says, you shouldn'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.

To do so, just create a Query based on your table and type

SumField: [Column1] + [Column2]

in a vacant Field cell.