Database Reference
In-Depth Information
WARNING
In a simple database like this one, counting the First Name field is enough to make reason-
ably certain that you're counting all the records. But in the real world, you want to be certain
every
customer is counted—even if the First Name field isn't filled in.
6.
Click OK
.
FileMaker adds the new field to the field list. Click OK to save your work.
You now have a field that helps you find out how many people are in the database.
That piece of information is much more useful than it sounds; you'll be using it to
find out interesting things soon.
If you squeeze this field onto the Detail layout and have a look in Browse mode, then you
see something altogether unimpressive: the total number of people in the database (the Status
toolbar already tells you this information). The real power of summary fields becomes appar-
ent when you combine them with Subsummary parts. Instead of counting all the people in
your database, you might want to count how many you have in each city or state (or both).
Perhaps you need to know how many are still living, or get counts by Zip code. Or you may
want to see how your contact list breaks down by city, gender, status, and mother's maiden
name (assuming you have all those fields in your database).
With the help of Subsummary parts, your humble “Count of People” summary field can tell
you all this. Instead of counting all the people in the database, it can count the records in dif-
ferent groups, and you can define those groups based on any field value.
Suppose you want to break your People List layout down by status, with one group for Act-
ive, one for Retired, and a third for Deceased. You also want to see how many people fall in
each group at a glance.
You already have the requisite summary field (the “Count of People” field you just created).
Now you need a Subsummary part:
1.
Switch to the People List layout, enter Layout mode and then choose In-
sert
→
Part
.
The Part Definition dialog box appears. Here's where you choose what kind of part
you want (you saw it way back in
Chapter 7
).
2.
Turn the “Sub-summary when sorted by” radio button
.
The list of fields on the right side of the window becomes active. A Subsummary part
is always hooked to a field.
