Linking record types Schema DDL
74 U929-J-Z125-9-76
Example of a 1:n relationship The relationship between customers and their orders is a 1:n relationship.A customer can place several orders, but each order can only be placed by one customer.
Figure 15: 1:n relationship between CUSTOMER and ORDERS
The logical relationship is created by defining the set CUSTOMER-ORDERS for the record types to be associated.
ORDERS 1
CUSTOMER
ORDERS
CUSTOMER
2
3
4
ERIC
ORDER: 1
CUST.: ADAM
RADIO
LAMP
5
1
ORDER: 4
CUST.: ERIC
ORDER: 3
CUST.: ERIC
ORDER: 2
CUST.: ERIC
LAMP
CLOCK
RADIO
2
30
1
KETTLE
RADIO
30
1
CLOCK
LAMP
KETTLE
100
5
10
ADAM