Using ChemFinder - CambridgeSoft

Chapter 6: Relational Data and
Subforms
Overview
Subforms allow you to work with multiple data
tables in a relational database. You should be
familiar with working with ChemFinder forms and
databases before proceeding to subforms.
Accessing Relational
Data Using Subforms
A subform is a special box within a form that
behaves like a separate form file. A subform is used
to display information stored within a database, but
it usually displays data from a different database (or
different table within the same database) than the
main form. A subform is usually linked to the main
form, so that retrieval of data in the main form also
retrieves related records in the subform.
Like other types of boxes, you can move select and
resize a subform on the main form. However, you
cannot select it by clicking inside it. You must click
the title bar. When you click inside a subform, you
you activate the miniature form inside the box and
can work within it.
Below are examples of subform use:
• You have data that is associated in a
“one-to-many” relationship. For example, you
want to view a chemical structure together with
its physical properties, stored in a separate
table.
• You are running a stockroom and you want to
store package sizes and prices in the same place
because they are related. Each chemical may be
available in lots of package sizes, and you
wouldn’t want to re-draw the structure every
time you added a new package. You can use a
subform so the physical property information is
entered once in the main form and the package
sizes and prices are entered many times in the
subform.
By linking these two data tables with a linking
field you can make these tables relational; one
table can interact with the other. The contents of
a linking field are not important, as long as they
are different for each record in the main form.
Various forms of ID numbers are often used as
linking fields. As you browse through the main
form, corresponding records in the subform
appear.
Creating a Subform
You create a subform, place form objects on it, and
connect the subform to a database just as you do a
regular form. For detailed information, see
“Chapter 3: Creating and Editing Forms.”
.To create a subform:
1. Click the Subform button .
2. Draw a large box on a form.
A subform appears with a border and scroll
bars.
ChemFinder 8 Chapter 6: Relational Data and Subforms • 103
Accessing Relational Data Using Subforms