Pathmaker Programming Guide

Coding Custom Services
Creating Services and Servers
4–48 067868 Tandem Computers Incorporated
Additional Considerations
for Coding NonStop SQL
Services
Coding custom services for a NonStop SQL Pathmaker application is much like coding
services for an Enscribe Pathmaker application, except that you include embedded
SQL code in the service.
For SQL-COBOL custom services, you should also consider these topics discussed in
the following pages:
Generating INVOKE statements for IPCs
Sending rows from tables and columns to services
Generating host variables
Using DEFINE names
Creating tabular screens
Generating INVOKE Statements for IPCs
When you have an SQL Table in an IPC, the Pathmaker product uses the information
you provide on the IPC Definition screen to generate INVOKE statements to create
COBOL records for the IPC request and reply parameters. The Pathmaker product
uses the names that you specify in the Request Reference Object column and the Reply
Reference Object column as the COBOL record names.
To avoid ambiguous name references in the generated code, the Request Reference
Object name and the Reply Reference Object name on the IPC Definition screen cannot
match the Logical File Name specified on the Logical File Entries screen.
Note You cannot directly SELECT into an IPC message; the Pathmaker product generates INVOKES from the
information you supply on the IPC Definition screen and creates records for the IPC message. Because
the IPC message might contain Enscribe DDL DEFINITIONs or RECORDs that are not valid host
variables, the Pathmaker product cannot make the IPC message a host variable.
Figure 4-11 lists the code that the Pathmaker product generates from the information
you supply on the IPC Definition screen.