U.M. (Mac OS)

Using data from related files 10-3
Understanding lookups
You look up data by first setting up a relationship between matching
data in the master file and a related file, and then defining a lookup to
copy data from a field in the related file into a field in the master file.
Match fields A field in the master file and a field in the related file that contain
values you want to use to find matching records. (A match field is
sometimes called a key field.)
For lookups, the values in the match fields don’t have to be equal
to each other. For example, you can set an option to copy the next
lower value when the match fields aren’t equal.
For relational databases, the values in the match fields must be
equal to each other.
Lookup source field
(for lookups only)
A field in the related file that contains the data you want to copy.
It’s the field the data is copied from.
Lookup destination field
(for lookups only)
A field in the master file that you want to contain the copied data.
It’s the field the data is copied to.
Relationship An expression you define that contains requirements which, when
met, establish a relationship between values in the match fields. (A
relationship is sometimes called a link or a join expression.)
Related record A record in the related file whose match field (according to the
relationship used) contains a value that’s equal to the value in the
match field of the master file.
Related field A field in the related file that contains data you want to access and
work with in the master file. After a relationship has been
established between data in the match fields, the data in a related
field can then be used in the master file.
You place a related field in a layout of the master file, either by
itself or in a portal. You can then work with the related data in all
modes.
In the master file, a related field name appears as
Relationship name::Related field name or as
::Related field name
Portal An object in a layout of the master file in which you can place
related fields. Use a portal when you want to access and work with
data from more than one related record in records of the master file.
You only need to place related fields in a portal if you want to work
with data from more than one related record.
Portals display data from related records in rows, one record in
each row.
This term Means