In a one-to-many relationship, one
record in a
table can be associated with one or more records in another table. For example, each customer can have many sales orders.
A one-to-many relationship looks like this in the
relationships graph:
In this example the
primary key field in the Customers table, Customer ID, is designed to contain unique values. The
foreign key field in the Orders table, Customer ID, is designed to allow multiple instances of the same value.
This relationship returns
related records when the value in the Customer ID field in the Orders table is the same as the value in the Customer ID field in the Customers table.
