Pathmaker Programming Guide

Creating a DB Requester Application
Pathmaker Application Development Overview
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Enscribe Keys
A DB requester application that accesses Enscribe files uses key fields to identify
specific records in a file.
Three categories of keys exist for Enscribe files:
Primary keys
Alternate keys
Courtesy keys
A Primary key is a field (or contiguous fields) in a file whose value is used to uniquely
identify each record in that file.
An Alternate key is a field or group of fields that can be used to identify one or more
records in a file. An Alternate key may contain duplicate values.
A Courtesy key is a system-generated number that uniquely identifies each record in
certain files. A Pathmaker application cannot display or use a Courtesy key.
A file can have either of the following:
A Primary key and any number of Alternate keys
A Courtesy key and any number of Alternate keys
Using Enscribe Keys
If an asterisk (*) appears to the left of a label on a DB requester Pathmaker application
screen, the label identifies a primary key field. If a plus sign (+) appears to the left of
the label on a DB requester Pathmaker application screen, the label identifies an
alternate key field. Courtesy keys cannot be displayed. The end user enters
information in these key fields on the screen to indicate to which record(s) an
operation applies.
Primary Key. An end user of a DB requester Pathmaker application that accesses
Enscribe files can read a particular record by designating a legal value in the screen’s
primary key field(s) (indicated by an *) and then pressing the appropriate function
key. After a record is read, it can be deleted or updated. The end user can add a new
record by filling in the primary key field(s) and any other necessary fields and then
pressing the function key for INSERT.
Alternate Key. An end user of a DB requester Pathmaker application can designate a
single record or set of records to be read by filling in the screen field(s) indicated
by a +. The + sign is associated with an alternate key. For example, if the end user
enters “SMITH” in the employee name field (Figure 3-7) and presses F7 for Read
Exact, the application will return the information for the first employee named SMITH
from the database. Then, by pressing F5–Read Next, the end user causes the
application to read the next SMITH in the database until there are no more SMITHs.