Technical data

Figure 5–14 Bachman Diagram of a Many-to-Many Relationship Between Two
Types of Records
PART VENDOR
VENDOR_SUPPLY
SUPPLY
ZK−1492−GE
PART_INFO
Figure 5–15 is an occurrence diagram of a many-to-many relationship between
two types of records. This diagram typifies a many-to-many relationship because
it shows a part (TAPE) being supplied by more than one vendor and a vendor
(SOUND-OFF CO.) supplying more than one part. You could add additional
vendors for a part by joining new supply records to a part and its new vendors.
You could also add additional parts supplied by one vendor by joining supply
records to the vendor and the new parts.
5–16 Database Programming with HP COBOL