User manual

150 | Working with related tables and files
Summarizing data in portals
You can summarize data that’s in a related field displayed in a portal. The portal
can contain records from a related table or from the same table (a self-join).
To summarize data in portals:
1. Create a calculation field in the table in which you want the total to be
displayed.
2. For the calculation field, define a formula that includes an aggregate
function for the type of summary calculation you want to perform.
For example, if you are in the Invoices table and want to define a calculation
to total the related values in the Price field of the LineItems table, use the
formula:
Sum(Line Items::Price)
3. Place the calculation field on a layout of the table in which it is defined.
See “Placing and removing fields on a layout” on page 116.
For more information about summarizing data in portals, see Help.
About lookups
A lookup copies data from another table into a field in the current table. After
data is copied, it becomes part of the current table (and remains in the table
from which it was copied). Data copied to the current table does not change
automatically when the data in the other table changes, unless the data in the
match field of the current table changes.
To establish a connection between tables for a lookup, you create a
relationship. Then you define a lookup to copy data from a field in the related
table into a field in the current table.
When you type a value in the match field of the current table, FileMaker Pro
uses the relationship to access the first record in the related table whose match
field contains a matching value. Next, it copies the value from the lookup
source field into the lookup target field, where the value is stored.
φμπ10_υσερσ_γυιδε.βοοκ Παγε 150 Μονδαψ, Αυγυστ 25, 2008 3:59 ΠΜ