Database Program Translation - Information Systems Reengineering, Integration and Normalization - page 194

Recompile
wi th enlarged
record size

Recompiled
Network
Programs

Network
Programs

Network
sc hema
+
se condary
indice

Network
Database
+
se condary
indice

Networ k
DBMS
Process

Fig. 5.7 Existing network database programs access “open” database

an embedded-SQL (relational database) program while the existing (out-of-dated)
network database programs are still in use. The out-of-dated network database pro-
grams should be gradually phased out or rewritten to use an embedded-SQL program.

5.6.1 Case Study of Translating Embedded-SQL to Network

Database Program

To illustrate the emulation algorithm in a case study, the following is an embedded-
SQL program that will be able to access the network database for the manufac-
turer's part supplier system of Fig. 5.8 .
Sample data from the network database could be as follows:

SUPPLIER
SUPPLIER_ID SUPPLIER_NAME ADDRESS

S1
S2
S3
S4

John's Co.
Michael Lee
Jack's Store
Michael Lee

32 Ivy Road
61 Clark Road
90 Dicky Road
61 Clark Road

P
PART_ID

A R T I T E M

PART_NAME UNIT_PRICE

P1
P2
P3

Sugar
Orange Juice
Beer

4
5
6