Expressions: Table Fields & Forms

[Guest]

Hello,

I have a question regarding expressions forms and tables. I have created a
rather complex expression in a form that is calculating projects based on
dates from other form fields. These other form fields are linked to table
field values.

The problem is I want to get the results of these expressions, that are
displaying in the field box back into the table corresponding to their
particular item.

1. Can I link a table field to a form field that is using an expression?

2. Alternatively, can I input the expression into the table, have it
calculated there, and then have the form field display the results, much as
the rest of the form fields do?

Thanks.

 

[John W. Vinson]

Hello,

I have a question regarding expressions forms and tables. I have created a
rather complex expression in a form that is calculating projects based on
dates from other form fields. These other form fields are linked to table
field values.

The problem is I want to get the results of these expressions, that are
displaying in the field box back into the table corresponding to their
particular item.

1. Can I link a table field to a form field that is using an expression?

2. Alternatively, can I input the expression into the table, have it
calculated there, and then have the form field display the results, much as
the rest of the form fields do?

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]